Optometry Admission Test (OAT)

Quick Facts

Get the “need to know” information at a quick glance.

Overview

The Optometry Admission Test (OAT) is produced by the American Dental Association (ADA) and the Association of Schools and Colleges of Optometry (ASCO) conducts the exam. The OAT is used to assess the skills of applicants seeking admission to optometry programs. The OAT measures general academic ability in the areas of the Natural Sciences, Reading Comprehension, Physics, and Quantitative Reasoning. 

Optometry program admissions offices review OAT scores as part of the process of determining which students to accept into their programs. Your performance on the OAT is just one factor considered by optometry schools, but the test is taken seriously by admissions offices, so it’s important to perform your best on the exam.

Unsure of how to register for the OAT?

Just visit www.ada.org/en/oat/apply-to-take-the-oat and click “Apply Now.”

Format

The OAT consists of 230 multiple-choice questions. The chart below provides a breakdown of the exam:

Cost

The fee to take the OAT is $475. This includes the fee to send score reports to the school(s) of choice that you identify when you apply to take the test.

You will be charged a fee of $40 per school for any score reports you request after the exam.

If you need to reschedule your OAT session, you may do so for a fee of $25 if you reschedule your test 31 or more days prior to your testing date. If you reschedule 6-30 business days prior to the exam, you will be charged a fee of $60. If you reschedule your exam 1-5 days before your test date, you will be asked to pay a fee of $100.

Scoring

Here’s a brief OAT score breakdown:

Each section of the OAT, such as the Survey of Natural Sciences, is scored individually. Then, the average of all sections is calculated to find your final score. 

Cumulative scores on the OAT range from 200 to 400 on each test in increments of 10.

Pass rate

You are not able to fail the OAT. So, what is an average score on the OAT? What is a good score on the OAT?

You already know how the test is scored and that a 400 is the highest possible score. The median score is 300. Many schools consider 325 – 350 to be good to excellent scores on the OAT. Check with the programs you are applying to in order to find out the average OAT score of candidates who are accepted.

Study Time

Many students want to know how much time should be spent studying for the OAT. There is no “one size fits all” answer; the time you spend studying depends on your content knowledge and how you tend to perform on standardized exams. 

Use our free materials to determine which sections of the OAT you have the most difficulty with. Then, plan to focus the majority of your studying time on your areas of weakness.

Most students who perform well on the OAT study for 4 – 6 months prior to the exam and spend 3 – 6 hours per study session. By studying well, not only will you get to know the content and the exam format, but you will feel more confident when you take the actual exam. 

You deserve to invest time in yourself to achieve your goals. Remember, once earned, no one can take your education away from you!

What test takers wish they would’ve known:

  • Answer every question. You are not penalized for incorrect answer choices. If you are uncertain of an answer, eliminate as many choices if possible, then go with your instinct.
  • Take the optional break time. This is an endurance exam. During your break, take some deep breaths and try to relax.
  • Begin studying now, not later. You absolutely cannot “cram the exam” on this one.
  • Break your study time into chunks. You can even set an alarm to remind yourself to take a break every 20 minutes or so.
  • Make studying as painless as possible. Wear comfy socks. Sit with your pet. Play music (if it doesn’t distract you). Have snacks nearby.
  • Plan study sessions with a friend. Even if your friend is studying for a different exam, you can motivate each other to stick to your goals.
  • Arrive at the testing center a few minutes early to reduce stress and wear layers in case the temperature is not ideal for you.
  • Don’t study the night before the exam. After spending so much time studying, give yourself a break. It is unlikely that you will have a major breakthrough the night before. It is, however, likely that you will stress yourself out more and potentially lose sleep.
  • Get plenty of sleep the night before the exam and arrive at the testing center hydrated and nourished from a healthy breakfast.

Testing information obtained from the ADA web site. www.ada.org

Survey of Natural Sciences

The Survey of Natural Sciences section has 100 questions. You will have 90 minutes to complete this content area.

This section emphasizes the following concepts:

  • Cells and Molecular Biology
  • Diversity of Life
  • Structure and Function of Systems
  • Genetics
  • Nomenclature of Organic Chemistry

So, let’s talk about them.

Cells and Molecular Biology

The Survey of the Natural Sciences usually includes biology questions related to cells and molecules. We’ll explore some important concepts to know.

Generalized Eukaryotic Cell

Each eukaryotic cell has a nucleus and other membrane-bound organelles.

A eukaryotic cell:

  • Contains rod-shaped chromosomes
  • Has vesicles to transport waste
  • Has vacuoles for storage and support
  • Contains a centrosome (microtubule organizing center or MTOC) if it is an animal cell; plant cells do not have MTOCs
  • Has lysosomes if it is an animal cell; plant cells do not have lysosomes
  • Has a central vacuole and chloroplasts if it is a plant cell; animal cells do not have central vacuoles and chloroplasts

Use the diagram below to review the parts of an animal eukaryotic cell:

Centriole: involved in the production of spindle fibers during cell division

Plasma membrane: protects the interior of the cell from the exterior environment. The plasma membrane is selectively permeable and it regulates the movement of ions and nutrients in and out of the cell-based upon their sizes and/or charges.

Vesicles: consist of fluid and encased in a lipid bilayer. They are involved in transport and enzyme storage.

Golgi apparatus: sorts lipids and proteins. The Golgi apparatus also modifies proteins and packages them for secretion while transporting lipids and synthesizing lysosomes.

Lysosome: contains enzymes which are used for digestion and the removal of waste, such as old organelles and endocytosed pathogens, like bacteria and viruses

Nucleus: stores and replicates deoxyribonucleic acid (DNA) and preserves chromosomes, enclosed in a protective double membrane. The nucleus also regulates the cell’s growth, metabolism, and reproduction.

Endoplasmic reticulum (smooth): synthesizes lipids and steroid hormones, detoxifies metabolic byproducts, does not have membrane-bound ribosomes

Endoplasmic reticulum (rough): has ribosomes attached to its membrane, synthesizes proteins through translation

Ribosomes: site of protein synthesis (translation); may be free-floating in the cytoplasm or attached to rough endoplasmic reticulum

Cytoplasm: the “jelly-like” liquid in which the cell’s organelles are suspended; helps facilitate cell signaling, communication, and transport

Mitochondrion: responsible for ATP (adenosine triphosphate) production and regulates cell metabolism. Many are found within the cell and referred to collectively as “mitochondria.”

Cytoskeleton: made up of microfilaments, supports the plasma membrane, and gives the cell structure

Unlike eukaryotic cells, prokaryotic cells (like those which make up bacteria) do not have organelles. However, prokaryotic cells do contain ribosomes and they have plasma membranes.

Cellular Metabolism

Cellular metabolism refers to the biochemical reactions, which are catalyzed by proteins called enzymes. Biochemical reactions take place in all cells belonging to living organisms. There are two main types of cellular metabolism: catabolism and anabolism, which have opposite purposes.

Catabolism degrades molecules, typically through oxidation, in which electrons are removed from the molecules. The process of catabolism generally takes place to allow energy to be gathered from the molecules. You may recall that processes that release energy are exergonic.

Anabolism usually requires cells to expend energy (instead of gathering energy) by transferring electrons to molecules. Reactions that require the expenditure of energy are endergonic. Anabolic processes build tissue by synthesizing the four classes of macromolecules: polysaccharides, proteins, lipids, and nucleic acids.

  • Polysaccharides: stored as carbohydrates, such as glycogen
  • Proteins: form an array of cell functions and are made up of amino acids
  • Lipids: hydrophobic molecules composed mainly of hydrocarbon bonds
  • Nucleic acids: Transmit and express the genetic information (DNA and RNA)

Diversity of Life

On the OAT, it is very likely to encounter several questions that ask you about living organisms. Let’s explore some concepts now.

Taxonomy and Biological Organization 

Living organisms are described by taxonomy, the process of grouping and describing identifying, classifying, grouping, and naming organisms.

The main taxonomic categories, from broadest to most specific, are: domain, kingdom, phylum, class, order, family, genus, and species.

The following table provides examples of taxonomy. Notice how each organism’s classification compares and contrasts with the classifications of the other organisms.

Did you see how similar the ermine and the ferret are? 

A little bit of genetic difference goes a long way. For example, the ferret is enjoyed as a household pet. Its deceptively cute cousin, the ermine, packs a punch as a half-pound animal with a crushing bite and the ability to take down prey several times its size. Ermines may be a wonder of nature – but they are not great pets!

Also, notice that listeria monocytogenes does not have a common name; this is typical of bacteria species.

Evolution

So, what accounts for the difference between the ferret and the ermine? Or even between your roommate and listeria monocytogenes? Yes, there is a taxonomic difference with regard to the latter two organisms.

The answer is evolution. 

On the Survey of Natural Sciences, you will probably encounter some questions about the evolution of species and natural selection. Remember that natural selection is to “survival of the fittest.” The best-adapted members of a species are the most likely members of that species to reproduce and pass on their traits to offspring.

Let’s take a look at some principles according to Darwin’s Theory of Evolution:

  • Populations (of species) evolve over time and space. A contemporary species differs from its ancestors, and populations of the species in different geographic regions may vary in characteristics and behavior. 
  • All species share common ancestors. A new species is formed once a population differs enough from the original species.
  • Evolutionary change is gradual and slow. 

Based on Darwin’s research, natural selection has four components:

  1. Variation: Individual organisms within populations vary by their appearances and behaviors.  
  2. Inheritance: Some traits are inherited (passed from parent to offspring), while other traits are mainly governed by environmental conditions.
  3. Rate of population growth: If a population produces more offspring than its environment is able to support, competition for resources and survival increases.
  4. Differential survival and reproduction: The members of a species that possess the best traits for survival are the most likely individuals of the species to produce offspring.

Take a look at the following definitions:

Structure and Function of Systems

The OAT typically includes some questions about human body systems. We’ll review a couple of these systems now.

The Endocrine System

This system produces and regulates the hormones which affect emotions, growth, organ function, metabolism, and reproduction. First, the endocrine glands release hormones into the bloodstream. Then, the hormones travel to cells throughout the body.

The hypothalamus, which is located in the brain, connects the endocrine system and the central nervous system. Your hypothalamus regulates sleep, hunger, and thirst, as well as emotional responses. 

Refer to the diagram below as you learn more about the endocrine system.

  • Pituitary Gland: The pituitary gland is located at the base of the brain. The pituitary gland produces several hormones, including:
    • Somatotropin: Stimulates growth 
    • Thyrotropin: Stimulates the production of thyroid hormones
    • Corticotropin: Stimulates the adrenal gland
    • Antidiuretic hormone: Helps to balance body fluids
    • Oxytocin: Triggers labor contractions
  • Thyroid Gland: Makes the thyroid hormones thyroxine and triiodothyronine; helps control metabolism, brain development, and growth
  • Thymus: Part of the lymphatic system as well as the endocrine system; produces T-cells which fight infection
  • Adrenal Glands: Each adrenal gland is located above a kidney. These glands have two parts:
    • Adrenal cortex: Produces corticosteroids, which balances salt and water, affects metabolism, helps control stress and immune responses 
    • Adrenal medulla: Produces epinephrine, which affects blood pressure and heart rate in stress responses
  • Pancreas: Produces insulin and glucagon, hormones that control glucose levels. Insulin also works to supply the body with energy.
  • Reproductive Glands (Ovaries and Testes): The testes (males) secrete androgens, which are hormones such as testosterone. The ovaries (females) secrete estrogen and progesterone. The hormones secreted by the reproductive glands are responsible for secondary sex characteristics in both males and females. 

The Respiratory System

Next, let’s review the human respiratory system. Use the diagram below to refer to the parts of this system.

  • Air enters the body through the nostrils and then travels to the nasal and oral cavities, which moisten and warm the air.
  • Next, air passes through the pharynx, which is a muscular tube that brings the air to the larynx. The opening of the larynx is close to the opening of the esophagus, and when you swallow, a flap called the epiglottis seals off your larynx.
  • The trachea (or windpipe) connects the larynx to the two main bronchial tubes: the left and right bronchus.
  • The left bronchus and right bronchus each branch out to your lungs. Irritants in the environment, such as smoke, cause your bronchial tubes to tighten.
  • Your lungs work constantly to produce oxygen for your entire body. Within each of your lungs, there are tiny sacs (called alveoli) which are surrounded by capillaries. The thin walls of the capillaries allow oxygen to pass from your lungs to your bloodstream and circulate throughout your body.
  • The diaphragm muscle contracts when you inhale and relaxes, pushing air out of your lungs when you exhale.

Genetics

Next, we’ll look at genes, chromosomes, and DNA, which are all concepts that tend to appear on the OAT.

Chromosomes are made of DNA and proteins. Because DNA is tightly packaged within chromosomes, DNA molecules are able to fit inside cells. Chromosomes also help to ensure that the replication of DNA is performed smoothly within cells.

Human cells usually contain 46 chromosomes arranged into 23 pairs. Only one pair of chromosomes, the sex chromosomes, are different in males and females. The other 22 pairs, which are called autosomes, are the same in males and females. Human cells are diploid because each cell contains two sets of chromosomes. One pair of chromosomes is received from each parent. Most, but not all, eukaryotic cells are diploid.

Because humans receive chromosomes from both parents, they receive genes from both parents. A gene contains codes for the proteins of body cells. Each gene, which is located on a chromosome, is composed of segments of DNA.

DNA is primarily located within the nuclei of cells. Just four chemicals compose DNA: adenine (A), guanine (G), cytosine (C), and thymine (T). These bases pair with each other (A pairs with T and C with pairs G) to form base pairs. The sequence of these base pairs can be thought of as a code that describes the information to maintain and build the cells of the body.

You may recall that DNA has a ”double-helix” appearance. In other words, it looks a lot like a spiraling ladder. The base pairs form the “steps” of the ladder, while sugar and phosphate molecules compose the sides of the ladder.

Nomenclature of Organic Chemistry

The OAT usually includes some questions about the basic nomenclature of organic chemistry. Let’s briefly review alkanes, haloalkanes, and alcohols.

Alkanes

Alkanes lack a functional group and are characterized by single bonds between carbon and hydrogen, or between carbon and carbon. Alkanes are also referred to as saturated hydrocarbons because their carbon atoms are saturated with hydrogen atoms.

Take a look at the two alkanes below as examples:

Based on chemical structure, there are three main types of alkanes: linear, branched, and cyclic.

Linear alkanes, such as decane and octane, have carbons that are bonded together in a long, chainlike structure. Branched alkanes are similar to linear alkanes, but they are branched out into alkyl groups instead of having a straight linear structure. The carbon atoms in cyclic alkanes are bonded together in a loop-like structure.

Haloalkanes

A haloalkane is an alkane in which a halogen acts as a replacement for a hydrogen. A carbon-halogen bond has a partial charge because halogen is electronegative and a carbon atom has a slightly positive charge.

The number of halogens on an alkane determines whether it is mono- (one), di- (two), or poly- (many). Specific examples of haloalkanes include fluoromethane, bromoethane, chloropropane, and iodobutane. 

Based on the structure, there are three main types of haloalkanes:

  • Primary (1°) haloalkanes: The carbon atom to which the halogen is attached to just one other carbon atom.
  • Secondary (2°) haloalkanes:  The carbon atom to which the halogen is attached is attached to two other carbon atoms.
  • Tertiary (3°) haloalkanes: The carbon atom to which the halogen is attached to three other carbon atoms.

Alcohols

Alcohol molecules contain a functional -OH group called a hydroxyl. Alcohol functional groups can be found in sugars, amino acids, and vitamins. 

The -e is dropped from the name of a hydrocarbon and -ol is added to give an alcohol its name. For example, the hydrocarbon butane loses its -e and gains an -ol to become butanol.

Alcohols can be classified into three groups:

  • Monohydric – Contains one alcohol group on the molecule
  • Dihydric – Contains two alcohol groups on the molecule
  • Polyhydric – Contains more than two alcohol groups on the molecule

The more alcohol groups on a molecule, the greater the water solubility. Conversely, greater the number of carbon atoms in an alcohol, the less soluble the alcohol is in water.

And that’s a basic overview of the Survey of Natural Sciences.

Reading Comprehension Test

The Reading Comprehension Test (RCT) has 50 questions. You will have 60 minutes to complete this test.

The following list describes the types of questions that you will see on the RCT:

  • Global Questions
  • Details
  • Tone 
  • Function
  • Inference
  • Support

On the Reading Comprehension Test, you will be presented with scientific passages and each passage will be accompanied by several corresponding questions. The RCT tests your ability to read and comprehend material. It does not test your prior content knowledge. 

On the RCT, you should focus on what is directly stated or implied by the text; don’t worry about anything you have (or have not) learned outside of the test. The answers will be supported by the text, so there’s no need to distract yourself by ideas that are not supported by the text.

As you read a passage, write down a word or phrase to describe each paragraph. You can refer back to your list of main ideas as you answer the questions. Because this strategy eliminates some of the need to “dig through” an entire passage, it will save you time.

If you encounter an unfamiliar term, use context clues to determine the meaning of the term. In other words, decide how the term is used in the sentence and use the text around the term to decipher its meaning. 

You can also determine the meaning of an unfamiliar term by breaking the word into its word parts. If you know the meaning of the parts of a term, you can usually decipher what the term means. 

The chart below provides some examples of common word parts that you may encounter in the scientific passages of the RCT.

Now, let’s talk about the types of questions that you will see on the RCT.

Global Questions

Global questions ask you to consider the “big picture” or overall meaning of passages and paragraphs. Essentially, they are about main ideas. After reading a passage, ask yourself what the main idea is before you read any questions. Sometimes questions can distract you with details, which are only included to support the main idea. While details are included for a reason, don’t confuse them with main ideas.

Read the following example excerpt. It discusses knuckling, an equine health concern. Ask yourself what the main idea is before you answer the question. Then, answer the question and check your response.

Knuckling is produced by disease of the suspensory ligament or of the flexor tendons, whereby they are shortened, and by disease of the fetlock joints. 

In young foals no treatment is necessary, unless there is some deformity present, since the legs straighten up without interference in the course of a few weeks. 

When knuckling has commenced, the indications are to relieve the tendons and ligaments by proper shoeing. The foot is to be prepared for the shoe by shortening the toe as much as possible, leaving the heels high; or if the foot is prepared in the usual way the shoe should be thin in front, with thick heels or high calks. For the hind feet a long-heeled shoe with calks seems to do best. Of course, when possible, the causes of knuckling are to be removed; since this can not always be done, however, the time may come when the patient can no longer perform any service, particularly in those cases in which both forelegs are affected, and it becomes necessary either to destroy the animal or obtain relief by surgical interference. 

In such cases the tendons between the fetlock and knee may be divided for the purpose of obtaining temporary relief. Firing and blistering the parts responsible for the knuckling may, in some instances, affect a cure; but a consideration of these measures belongs properly to the treatment of the disease in which knuckling appears simply as a sequel.

Who would find this passage most helpful?

  1. a layperson who is unsure whether his horse is suffering from knuckling
  2. a veterinarian who specializes in exotic pets
  3. a researcher analyzing the behavior of injured farm animals
  4. a veterinarian who wants to better understand the first signs of knuckling 
  5. a layperson who needs to put shoes on a horse with knuckling

While this question did not contain the words “main idea,” it did ask you to assess the main idea by considering the passage as a whole. The correct answer is E. Choices A and D are incorrect because the passage focuses on treatment, not diagnoses. Choices B and C are incorrect because they are too off-topic.

Details

Many questions on the Reading Comprehension test will be about the details in the passages. You may be asked how details support the main idea. Other questions about details may ask you how the details relate to one another, or simply what the details state.

Read the sample excerpt below.

No more important lesson is to be learned than that which relates to the ways in which milk is contaminated with germ life of various kinds; for if these sources of infection are thoroughly recognized they can in large measure be prevented, and so the troubles which they engender overcome. Yeasts and some fungi found in milk are capable of growth, but more particularly, the bacteria are as well.

Milk is a suitable bacterial food. The readiness with which milk undergoes fermentative changes indicates that it is well adapted to nourish bacterial life. Not only does it contain all the necessary nutritive substances but they are diluted in proper proportions so as to render them available for bacterial as well as mammalian life.

Of the nitrogenous compounds, the albumen is in readily assimilable form. The casein, being insoluble, is not directly available until it is acted upon by protein-dissolving enzymes like trypsin which may be secreted by bacteria. The fat is relatively resistant to change, although a few forms are capable of decomposing it. Milk sugar, however, is an admirable food for many species, acids and sometimes gases being generally produced.

What is the significance of the detail that nutritive substances are diluted in milk?

  1. The detail shows why milk is suitable for mammals.
  2. The detail shows why milk is resistant to bacteria.
  3. It explains the function of enzymes like trypsin.
  4. It helps show why bacteria are able to feed on milk.
  5. It helps to show why milk is suitable for human consumption, even if it contains small amounts of bacteria.

It’s important to think about the overall main idea of this question. Then, you can consider the details. Since the main idea relates to bacteria, you can eliminate choices A and C, which are definitely incorrect. Next, you can eliminate B because the passage implies the opposite. When considering D and E, you may overthink the question.

Is it true that since the nutritive substances in milk (which bacteria feed on) are diluted, and therefore the bacterial colonies will be diluted as well, making the milk suitable for people? 

If you begin thinking thoughts like that, you are wandering down what we’ll call a rabbit hole. D is clearly correct and does not lead you down a stray path full of what-ifs?

Tone

The tone of a passage refers to how the author’s word choice reflects his or her attitude or emotions. The passages on the OAT Reading Comprehension Test will not reflect strong emotions from the author.

So, how can you tell how the authors feel about a subject, or what their biases are?

The answer is to consider the connotations of the words in the passages. Terms have both connotations and denotations. Denotation refers to the dictionary definition of words and connotation refers to the emotions and ideas associated with a word. 

For example, imagine that someone tells you his coworker as outgoing. You would probably think that the coworker is pleasant. Outgoing has a positive connotation. Now, imagine that someone tells you that is coworker is loud. You’re probably glad that you don’t work with that coworker!

Outgoing and loud can both be used to describe people who talk a lot. However, the denotations of these words are quite different.

Take a look at the examples of connotations and denotations in this chart:

Keep in mind that not every word has a positive or negative connotation. For example, chair, walk, speak, paper, and hear all have neutral connotations.

Consider this excerpt:

While it has been shown that it is practically impossible to foretell whether the milk of any reacting animal actually contains tubercle bacilli or not, still the interests of public health demand that no milk from such stock be used for human food until it has been rendered safe by some satisfactory treatment.

Find the word “demand” in the excerpt. Notice that the author could have made a different, less strong word. Why does the author use “demand”? 

He wants to stress the point that public health is very important and should be taken seriously. Therefore, his town could be described as grave, certain, or firm.

Now, read this brief excerpt:

Of course, an experienced eye can see, and a trained hand can feel, slight alterations or variations from the normal that are not perceptible to the unskilled observer. 

What do the words in bold tell you about the author?

The selected words imply that the author is an authority who is experienced and trained. Of course is a very presumptuous, sweeping phrase. Instead of referring to a layperson or to someone who has not been trained in [the field of interest], the author uses unskilled observer. Understood literally, an unskilled observer has no skills!

Based solely on this small section of text, a reader might describe the author as self-important, pompous, haughty, or arrogant. The author’s tone delivers the message that he is (or considers himself to be) an expert. His tone also lends the idea that others are beneath him in terms of ability or practice.

Function

Some questions on the test will ask you about the function of phrases, sentences, or paragraphs. It is also likely that you would be asked to consider how an additional sentence (or two) would function in a passage. 

Read this sample excerpt:

Very strong bee colonies, no matter where kept, will keep themselves warm and will survive any degree of cold, but there is no doubt that their vitality and ability to stand wintering will suffer a great deal thereby, causing dwindling in the spring. Cellar wintering is at present general in Minnesota. The bee cellar should be warm, dry, dark and ventilated. The bees should not be disturbed during their winter sleep by pounding, jarring, shaking and feeding. 

Which sentence, if true, would be best for the author to include next?

  1.  Mice also may cause the bees to get excited and perish. 
  2.  It is important that beekeepers adhere to these principles.
  3.  Studies show that disturbing hives during the winter months will cause the bees to scatter and die.
  4. Research indicates that colonies kept in Minnesota and other states in the northern half of the U.S. are more likely to dwindle during the winter months.
  5. Dampness can negatively impact colonies in a variety of manners.

Now, let’s eliminate some choices. Choice A introduces a new idea, so we can eliminate that answer immediately. Choice B and C both make some sense, so let’s plan to go back to them. 

We can eliminate D because it compares bees in various states. In the text, the author is only interested in bees in Minnesota; the author is not concerned with how other bees are faring. 

Choice E jumps back to a previous idea about how dryness versus moisture.

So, we must choose between B and C. Both choices are linked to the last sentence. However, C gives strong support and B does not give any evidence. Choice C is correct.

Inference

Sometimes on the test, you will need to make an inference, or a guess based on what the text states. Remember that no outside knowledge is needed on the exam?

So, how can you make a guess about something you are unfamiliar with?

The answer is to use the text. Even if an answer is not directly stated, it will be supported by what is directly stated. Do stray from what is said in the passage. 

Read this sample excerpt:

It is stated that one of the white horses recently presented in Russia has blue eyes. I can scarcely credit this, but think it must be a true albino, with the gray-pink coloured eyes they generally have, or possibly the blue eye is that peculiar to the albino cat and horse, as I have never seen an albino horse or cat with pink eyes but a kind of opalesque colour, or what is termed “wall eye.” No doubt many of my readers have observed the differences in the white of our horses, they mostly being the gray-white, with dark skin; but the purer white has a pink skin, and is much softer and elegant in appearance. It is the same with our white cats.

Which of the following statements is supported by the passage?

  1. Similar eye colors are present in both horses and cats with albinism.
  2. Pink eyes are not a genetically possible trait in cats or in horses. 
  3. Cats with dark skin and white fur feel softer to humans than cats with pink skin and white fur.
  4. Cats with pink skin typically exhibit a grayish-white coat color.
  5. Cats with albinism tend to have grayish-pink eyes.

Think about the language of the question. You are looking for a statement which is supported by the text; you do not need to be concerned with whether the statement is accurate. Choice A is correct. Each of the other statements either a) cannot be inferred or disproven by the passage or b) are a misstatement and are untrue based on the passage.

Support

Think back to the function question you answered about bees. You decided which statement would be best to include in the passage. Part of your decision was based on support.

Support helps to strengthen, as opposed to weaken, ideas in a passage. Some questions on the test are likely to ask you to assess the strengths or weaknesses of arguments and ideas. 

For example, you may be asked what new information would weaken the author’s ideas.

Read the following passage.

Gardeners, birdwatchers, and farmers often consider S. carolinensis, the eastern gray squirrel, to be a nuisance. This small mammal is known to pilfer commercial bird feed and feed on tree nuts. Although the eastern gray squirrel may be an irritation at times, it fills a beneficial role in its environment.

Members of the eastern gray squirrel species dig shallow holes in the ground and bury their food stores for later, but only retrieve about 70% of the food they bury. In time, several of a squirrel’s buried walnuts and acorns can develop into full adult trees. Therefore, the gray squirrel is quite a seed-spreading boon to tree populations.

The eastern gray squirrel is also an important source of protein for birds of prey, snakes, and carnivorous mammals. The numbers of several species would dwindle without the availability of squirrels on which to feed.

Which of the following statements would most significantly weaken the author’s argument?

  1. There are several species of predators that do not eat squirrels.
  2. Many nuts and seeds deposited by squirrels never even develop into seedlings.
  3. Squirrels have value not only because they help other species, but because they are interesting creatures themselves.
  4. Squirrels pose an incredible amount of competition to many species of native and protected birds, which rely on some of the same foods.

The author’s main argument is that squirrels help the environment. D gives evidence that squirrels can be destructive to the environment; therefore, this choice weakens the argument. D is the correct answer.

Choices A and B could be used to weaken specific supportive details included by the author, but these choices do not tackle the “big picture.” Choice C does not weaken the argument.

And that’s some basic information about the Reading Comprehension Test.

Physics Test

The Physics Test has 40 questions. You will have 50 minutes to complete this content area.

This section emphasizes the following concepts:

  • Scalars and Vectors
  • Linear Kinematics
  • Statics and Dynamics
  • Energy and Momentum
  • Simple Harmonic Motion

So, let’s talk about them.

Scalars and Vectors

Quantities that can be described using real numbers (2, -13, 600, π, etc.) are called scalars. Other quantities can only be described by both a number and a direction – these are called vectors (v).

Here are a couple of examples:

Scalar: The wind is blowing 16 km/h. (Speed)
Vector: The wind is blowing 16 km/h due east. (Velocity)

We can use arrows to describe vectors. Each arrow has a tail and a tip:

The length of the arrow represents the number, and the direction of the arrow represents the direction of the vector.

To add two vectors, match the tail up with one vector to the tip of the other vector. Take a look at how the tip of A is matched to the tail of B to describe A + B:

We can rearrange the two vectors so that the tip of B is matched to the tail of A:

Notice that this arrangement still describes A + B. If both A and B are vectors, then A + B = B + A – just as, for example 2 + 4 = 4 + 2.

Next, let’s subtract a vector from another vector. If C and D are vectors, C – D = C + (-D). So, what is -D? 

It’s the opposite of D. We describe -D as having the same magnitude (length) of D, yet it goes in the opposite direction:

So, to subtract D from C, we just add C to -D:

It is important to know that vector subtraction, unlike vector addition, is not communicative. In other words C – D does not generally equal D – C. This is analogous to the scalar situation: 2 – 4 ≠ 4 – 2.

Next, let’s multiply a vector. Remember that the length represents a scalar value and direction represents the direction of a vector:

If A is multiplied by a negative scalar (such as -2), we represent A by reversing the tip and the tail.

Linear Kinematics

Questions about linear kinematics often appear on the Physics Test. Let’s talk about some important concepts.

Displacement

In physics, the term displacement refers to a change in an object’s position. Displacement is calculated by subtracting an object’s original position from its final position.

For example, if an object starts at the origin and moves to the point (0,20), the displacement is given by the vector (0, 20) – (0,0) = <0, 20>. If the object then moves back to the origin, the displacement would be (0,0) – (0,20) = <0, -20>. Though the distance traveled is the same in both cases, the displacement changes.

It’s also important to remember that displacement only accounts for the initial and final positions of the object. It does not account for the path that the object took.

Imagine that an object starts at 5 cm, then moves to 10 cm, then moves back to 5 cm, and finally moves to 25 cm. We do not account for the displacement any differently than if the object had moved straight from 5 cm to 25 cm – the displacement is still 20 cm because the difference between the initial position and the final position is the same in both cases. The total distance that the object traveled is a different story:

5 cm to 10 cm = 5 cm
10 cm to 5 cm = 5 cm
5 cm to 25 cm = 20 cm
Total distance = 30 cm

Now, imagine that a runner sprints 400 meters around a circular track and ends up back at her starting point. Since her initial position and her final position are the same, her displacement is 0, although her total distance is 400 meters. 

Velocity

While we use displacement to describe how much an object’s position changes, we use velocity to describe how rapidly the object’s position changes. For example, the position of a car traveling 55 mph changes by 55 miles each hour.

Average velocity is calculated by dividing displacement by time.

Average velocity = displacement ÷ time

Let’s go back to the example of the object moving along a meter stick. Imagine that the object’s initial position is 90 cm and it reaches the 20 cm position in 3 seconds and the 70 cm position in 5 seconds.

We calculate the average velocity as -20 cm (displacement) ÷ 5 s (time). The average velocity is -4 meters per second. The total distance of the object is 120 cm. So, the average speed of the object is 120 cm divided by 5 seconds or 24 cm per second.

Notice that this doesn’t imply that the object is always traveling at this average velocity. Sometimes it might be faster. Sometimes it might be slower. It might even stop or reverse directions at some point. This is the average velocity, not the velocity at a given instant.

Acceleration

While velocity describes how quickly an object’s position changes, acceleration describes how quickly an object’s velocity changes. We describe average acceleration by dividing the change in velocity by time. 

Take a look at the formula below:

Average acceleration = (vf – vi) ÷ (tf – ti)

We can calculate average acceleration by subtracting the initial velocity from the final velocity and dividing that number by the initial time subtracted from the final time. 

So, let’s say that an object moves in a straight path along a meter stick. Its initial velocity is 4 cm/s and its final velocity is 10 cm/s. The change in velocity takes place in 2 seconds.

The average acceleration is (10 cm/s – 4 cm/s) divided by (2 s – 0 s). The object’s average acceleration is 3 cm/s².

Statics and Dynamics

We just reviewed linear kinematics, which describes the position, velocity, and acceleration of objects. Now, we’ll look at statics and dynamics, which focuses on explaining motions and forces.

Newton’s First Law

Newton’s first law states that the velocity of an object will not change unless a net force acts upon the object. Without interference from a net force, an object at rest remains at rest and an object in motion remains moving without a change in velocity. This law is also called the law of inertia.

An object with a greater mass has a greater inertia. For example, an object with a mass of 10 grams has an inertia that is 10 times greater than an object with a mass of 1 gram.

Inertia refers to the tendency of an object to remain in a state of rest or continue at a constant velocity. Imagine that a ball with a mass of 100 kg is rolling towards you. It would be 100 times more difficult to stop than a ball with a mass of 1 kg.

Newton’s Second Law

According to Newton’s Second Law, there is a direct relationship between the force exerted on an object and the acceleration that object experiences. Specifically, F = m•a, where F is the force in Newtons, m is the mass in kg, and a is the acceleration in m/s². This means that, for a given force, a lighter object will accelerate more quickly than a heavier one.

Since forces have both a magnitude and a direction, they are vectors (not scalars).

Take a look at the examples below, which show two different forces acting upon an object. Notice that the net force is equal to Force 1 + Force 2.

Newton’s Third Law

According to Newton’s third law, every action has an opposite and equal reaction. For example, imagine that Object 1 has a mass of 50 kg and Object 2 has a mass of 100 kg. Object 1 pushes Object 2 with a force of 50 N (newtons).

The force of Object 1 on Object 2 is 50 N and the force of Object 2 on Object 1 is -50 N. Although the forces are opposite but equal, the acceleration of the two objects is not:

Average acceleration of Object 1 = (-50 N) ÷ (50 kg) = -1 m/s².  
Average acceleration of Object 2 = (50 N) ÷ (100 kg) = 0.5 m/s².  

Notice that the mass of each of the two objects affects their accelerations.

When you stand on the ground, gravity is pulling you down with a force of 9.8m, where m is your mass. That means that the ground is pushing back up at you with that same force. This might seem surprising: we don’t normally think about the ground as pushing on our feet. But think about what would happen if this were not the case. If the only force acting on us was gravity, our acceleration downward would be F/m, or (9.8m)/m = 9.8. Since we aren’t hurtling through the ground, there must be a counterbalancing force from the ground.

Energy and Momentum

On the OAT, you can expect to see some questions that ask you about energy and momentum. Let’s review some concepts.

Work

Work is measured in joules (J). When both vectors have the same direction, work can be described using the formula W = Force × Distance. If the force is 20 N and the distance is 10 meters, you can multiply the two numbers to determine that the work is 200 J.

Same Direction:

Keep in mind that the two vectors (force and direction) are not always in the same direction.

Different Directions:

In this case, the formula W = (Force × Distance)cosθ can be used. The θ is simply the measure of the angle between the force and the distance.

Note that Work = Force × Distance is really the same as (Force × Distance)cosθ in special cases in which the directions are the same. Why? Because in those cases cosθ = 1.

Power

Power measures how quickly work is done. For example, if 40 J is done in 10 seconds, the power is 4 J/s or 4 W (watts). You probably hear about watts when talking about appliances. For example, a 200W air conditioner uses 200 watts of power.

Notice that although W is in italics when it refers to work, W is not in italics when it refers to watts.

The faster work is done, the greater the power. If 100 J is done in 2 seconds, the power is 50 W. If 100 J is done in 1 second, the power is 100 W.

Also notice that because power is work divided by time, W = Pt. For example, a machine has an output of 200 W. How much work can the machine do in 1 hour?

An hour is 3,600 seconds (60 minutes × 60 seconds). So, the work is:

W = (200 W)(3,600s)
W = 720,000 J or 720 kJ

Kinetic Energy

Objects that move doing work isn’t necessary(and therefore are not at rest) have kinetic energy. Kinetic energy (KE) = ½mv². Imagine that an object is 10 kg. It moves with a velocity of 4 meters per second. We can use the formula to determine the kinetic energy of the object:

(KE) = ½mv² = ½(10)(4)² = ½(10)(16) = ½(160) = 80 J

Kinetic energy is scalar; it is concerned with the speed of the object, not the direction in which the object is traveling. Try the following question on your own before reading the correct answer:

An object with a mass of 55 kg is traveling at a velocity of 3.87 m/s. What is the object’s kinetic energy?

  1. 42.477 J
  2. 106.425 J
  3. 212.85 J
  4. 411.865 J

The correct answer is choice D. Be sure to square 3.87 to get 14.977. Multiply that number by 55, then divide your answer in half to get 411.865.

Simple Harmonic Motion

Simple harmonic motion refers to the motion of a mass on a spring that is subjected to a linear elastic restoring force. There are no other forces like friction or air resistance.

Imagine the spring and the object in the diagram you just saw. If the spring in the object is in motion, it will remain in motion unless it is stopped by a force (remember Newton’s first law). Because the spring is attached to the object, the spring exerts a force on the object.

Hooke’s Law tells us that the force exerted by a spring is Fspring = -kx, where k is the spring constant and x is the displacement of the spring from its resting position. The spring constant is a property of the spring itself. A stiff spring – like the one in a car’s suspension – will have a much higher spring constant than a weak spring found in a cell phone.

The x in Hooke’s Law tells us that the spring exerts more force the further we stretch it. Finally, the negative sign reminds us that this is a restoring force. If we stretch the spring from its equilibrium position, the spring pull back in. If we compress the spring from its equilibrium position, the spring will work to push the object back to equilibrium.

Because the spring is always attempting to restore the object to its equilibrium, we say that the spring has a linear elastic restoring force.

Elastic potential energy = ½kx²

The elastic potential energy represents the energy that is stored when the spring is compressed. This energy could be transformed into other kinds of energy, including kinetic energy.

Let’s say that the spring has a constant of 100 N/m and it is stretched 2 meters. What is the elastic potential energy?

EPE = ½kx² = ½(100 N/m)(2 m)² = 200J

And that’s some basic info about the Physics Test!

Quantitative Reasoning Test

The Quantitative Reasoning Test (QRT) has 40 questions. You will have 45 minutes to complete this content area.

This section emphasizes the following concepts:

  • Algebraic Equations and Inequalities
  • Percentages
  • Scientific Notation
  • Lines and Slope
  • Perimeter and Area
  • Circles
  • Trigonometry

So, let’s talk about them.

Algebraic Equations and Inequalities

While taking the OAT, you are very likely to encounter equations and inequalities with variables. We’ll review some important concepts now.

Linear Equations and Inequalities

Linear equations are written in the standard form ax + by = c and they describe a line when they are graphed.

Here is an example of a linear equation in standard form:

x + 4y = 13

Notice that the blue point (5,2) represents x = 5 and y = 2 and 5+4∙2 = 13 satisfies the equation. This is true of every single point on the line.

Not all linear equations are presented in standard form. You may need to work with linear equations that don’t initially appear to follow the ax + by = c format.  

These are a few examples of linear equations that are not written in standard form:

y−5 = −3(x+5)
2x = -4y
3x – 4 + 4 = -10 + 4
x + 9 – 9 = 12 – 9

Let’s work with a linear equation that is not in standard form:

4y – 12 = -1x + 1

First, add 1x to each side of the equation:

4y – 12 + 1x = 1 

Next, add 12 to each side of the equation:

4y + 1x = 13 or 1x + 4y = 13

Now your equation is in standard form.

Linear inequalities are treated the same way as linear equalities. The biggest difference is that instead of an equals sign, linear inequalities have a greater than sign (﹥), a greater than or equal to sign ( ≥ ), a lesser than sign (﹤), or a lesser than or equal to sign ( ≤ ). There is another important algebraic difference. When you multiply or divide both sides of an inequality by a negative number, you need to switch the direction of the inequality. For instance,

-x-2 < -3

Becomes

x+2 > 3

When you divide by -1. To verify that this is true, notice that x = 2 satisfies both equations.

Quadratic Equations

A quadratic equation forms a parabola () when they are graphed. These equations contain squares and their standard form is a² + bx + c = 0. Just like linear equations, quadratic equations do not always initially appear in standard form.

Let’s look at an example of a quadratic equation and solve it:

 x² + 4x -5 = y

You found the both solutions to the quadratic equation!

Percentages

Next, let’s recap working with percentages, which frequently appear on the exam as well. 

Remember that a percentage can be written as a fraction over 100. So, 25% = 25 / 100, 13.5% = 13.5 / 100, and so on. To convert a percent to a decimal, move the decimal 2 places to the left (because there are 2 zeros in 100). So, 64% = 0.64.

Practice your knowledge of fractions, decimals, and percentages by answering the following question.

Which of the following is greatest in value?

11.5 / 1000, 0.0130, 0.12%

Let’s convert all of the numbers to percentages in order to compare them more easily. 

The number 0.0130 is easy–we just need to move the decimal two places to the right to get 1.3%. 

Now, let’s think about 11.5 / 1000. The number 1,000 has three decimal places, but we want to think about 11.5 represented over 100. We can drop 1 zero from 1,000 to get 100 as our new denominator. Then, let’s move the decimal on top 1 place to the right to account for the 1 zero we removed from the denominator.
(11.5 / 1000 = 115 / 100 = 1.15%)

When we compare 1.15%, 1.3%, and 0.12%, we can conclude that 1.15% is the greatest number.

Scientific Notation

If you’re a little rusty on scientific notation, remember that it is used to show a number between 1 and 10 multiplied by a power of 10. Sometimes, questions on the Quantitative Reasoning Test are most easily solved by using scientific notation. 

Take a look at the chart below to compare numbers in standard form to numbers expressed using scientific notation.

Now, let’s try a sample problem:

(4.2 x 10⁵)(2 x 10⁷)

Multiplication is commutative. In other words, it does not matter how you order the numbers that you are multiplying.

(4.2 x 10⁵)(2 x 10⁷)   = (10⁷ x 10⁵)(2 x 4.2)  

When we multiply two numbers with exponents, we add the exponents. So, 10⁷ x 10⁵ = 10¹². The numbers that aren’t powers of 10 multiply normally.

(10¹²)(2 x 4.2)  = (10¹²)(8.4)

Did you notice that now the problem is really just a number expressed in scientific notation? Express the number in standard form to get 8,400,000,000,000 as the answer.

You’re all done!

Lines and Slope

On the Quantitative Reasoning Test, you are likely to see some questions which require you to think about lines and their slopes. Let’s start by reviewing slope.

Slope

The formula y = mx + b can describe any line on a coordinate plane (graph). The x and y values of any two points on the line may be used in this equation. The m value represents the slope (steepness) and the b value represents the y-intercept (where the line crosses the y-axis).

Consider this example question:

At what point does a line passing through point T (6, –2) and point U (8, 4) intersect the y-axis?

So, we have the x and y values of two points. We are being asked to find the y-intercept, but we don’t have the slope yet.

This is the equation to find the slope of a line:

Either point may be assigned to x₁ and y₁. Just make sure that whichever point you use for the x₁ value is the same point that you use for the y₁ value. Let’s use point T for x₁ and y₁. 

Plug the values from the two points into the formula:

Now that we have the slope (3,) we can plug all values into the formula y = mx + b to find the slope (b). We can use either point to find the answer. Let’s plug in the values from point U:

y = mx + b
4 = (3)8 + b
4 = 24 + b
-20 = b

So, the y-intercept of the line is -20.

Points on a Line

On the test, you may need to determine the distance between two points on a line. In order to determine the distance, you will need to use the distance formula:

Let’s use the formula to find the distance between points A and B on the graph below.

Our values are (-1,1) for A and (3, 4) for B. So, let’s use the values from A for (x₁, y₁) and the values from B for (x₂, y₂). Plug the values into the formula:

So, the distance between C and D is 5.

Perimeter and Area

The Quantitative Reasoning Test usually includes some questions about perimeter and area. You probably remember that perimeter is the sum of all sides of a figure and area describes the space inside a figure. Area is expressed in square units.

Use the table below to view some examples of perimeter and area.

Now, try solving an example question:

Derrick is planning to sow seeds on a rectangular field that is 100 meters long and 50 meters wide. A bag of seeds weighs 3 lbs. If Derrick needs to plant 5 pounds for every 300 square meters, how many bags of seeds does he need to buy?

This question is asking you to consider the area of the field. The area of a rectangle is length x width. The field is 100 m x 50 m, so the area is 5,000 m².

Derrick needs 5 pounds of seeds for every 300 square meters. You can divide 300 by 5 to determine that Derrick needs 1 pound of seeds for every 60 square meters. Divide 5,000 by 60 to determine that Derrick needs 83.333 pounds of seeds.

The seeds are packaged in 3 lb. bags. Since 83.333 divided by 3 is 27.778, Derrick will need 28 bags of seeds since he cannot buy a fractional bag. This is not the same as rounding. Even if Derrick only needs to use 27.1 bags, he would need the purchase 28 since he needs at least 27.1.

Circles

You are likely to encounter questions on the Quantitative Reasoning test which ask you about circumference and area. Circumference is similar to perimeter; it is the measurement around a circle. Review these two formulas:

Circumference = 2πr
Area of a circle = πr²

Remember that the diameter (d)  is the distance from one side of a circle to the opposite side and it can be represented by a line drawn through the exact center of the circle. The radius (r) is half of the diameter.

Take a look at the diagram below. We will find the circumference and the area of the circle.

So, let’s divide the diameter (6.4) by 2 to get the radius (3.2). Now, plug the radius into the formulas to find the circumference and the area of the circle.

Circumference  = 2πr = 2π(3.2)  = 20.106 in,

Area  = πr²  = π(3.2)²  = 32.17 in.² 

We found both the circumference and the area of the circle!

Trigonometry

The test often includes questions related to trigonometry, which deals with angles. Let’s review a couple of concepts.

Sine, Cosine, and Tangent

Sine, cosine, and tangent describe ratios in a right triangle (a right triangle has an angle which equals 90°). The hypotenuse is the side opposite the right angle. The adjacent side connects the right angle and the angle of interest. The opposite side is across from the angle of interest.

The graphic below provides an example triangle and the formulas for sine, cosine, and tangent.

Remember the mnemonic SOH-CAH-TOA. This means that sine (S) is opposite (O) over hypotenuse (H), while the C and T stand for cosine and tangent respectively.

Imagine that Angle X  in the figure is 60° and that the hypotenuse is 10 units and the adjacent side is 5 units. The cosine of the angle would be cos(60°) = 5 ÷ 10 = ½.  

You just need to remember which side to divide by which in order to find the sine, cosine, or tangent. Then, just plug the values into the formula!

Arc

Arcs also deal with angles. An arc can be described as part of a circle’s circumference. You can use the measure of an angle inside of a circle to determine the value of an arc. Use the circle below as an example.

Arc A is a portion of the circle’s circumference. In order to find the measure of Arc A, use the formula Arc length = (Ɵ / 360)(2πr). The symbol that you see as the numerator in the formula just means to plug in the value of the angle (in this case, 61). So, let’s find the length of the arc using the formula. 

Arc length  = (61 / 360)(2π7)  = 7.452 ft.

And that’s some basic info about the Quantitative Reasoning Test!