ACT Science

Wrong Answer Types

If you can figure out what those errors are, identify them, and figure out how to stop making, you’ll end up getting a much higher science score. Unlike math and English, where you truly “earn” your points, the ACT science section has nothing to do with knowledge. It’s not as if you don’t already have what it takes to get a perfect score - if you have a functioning brain, the ability to read, and the ability to look at charts and graphs, you have all the tools you need to ace the ACT science section. You’re just carrying some “error baggage” that’s preventing you from getting that perfect score!

In this section, we’re going to be cataloguing every single mistake type that a student makes. With that in mind, let’s quickly discuss the types of mistakes that you can make on ACT science:

  1. Wrong study/figure/graph. Did you not look at the right study, the right figure, the right graph, etc.? Were you reading or analyzing the wrong information?
  2. Wrong direction. Did you pick highest instead of lowest? Did you say the temperature was going up when it should have been going down?
  3. Wrong “because.” For instance, if a question asks, “did this graph show that this element was suitable for this environment,” did you say “yes,” but pick the wrong reason for that yes?
  4. Cannot be Determined. Does the Cannot be determined answer choice distract you? Do you feel it cannot be the right answer?
  5. Didn’t know the random stupid science fact. You know that one random problem on each science section that actually test your science knowledge?
  6. Wrong “inference.” You know the problems which ask you things like: “if the scientist wanted to test his hypothesis’ accuracy, what could he do in the next experiment to provide a control environment?” Did you not eliminate the choices quickly enough?
  7. Wrong number. Did you read 50mm, but put 500mm? Did you count 4 slides instead of 3?

THAT’S IT. Every single ACT Science question that you get boils down to one of these seven errors. The goal after every test is to figure out which ones you’re making wrong, and how frequently.

Most will fit quite neatly into one of the seven categories, but if something doesn’t, you can either put two or more errors there or you can just pick the error that works best.

Often times, students improve simply by realizing which errors they’re making most commonly. You’ll almost always see that most of the errors are in the same categories, and with a deeper understanding of what you’re doing wrong, you’ll quickly come to realize that these errors are just opportunities in disguise.

Think about them, understand them, eliminate them, and your score will skyrocket in no time! In this section, we will walk through each error type, giving you a collection of tips and tricks that’ll help eliminate each one out.

1. Wrong study/figure/graph

This might seem like a simple, “oh silly me” sort of error, but if you’ve made it more than once on your science section, you should be extremely concerned. As we’ve already discussed, “careless errors” aren’t to be ignored - they’re to be focused upon, obsessed with, and ruthlessly eliminated.

If you looked at the wrong study, figure, or graph even once on your ACT science section, you need to set up a system to eliminate these kinds of errors in the future.

First, a key concept: Anything “under” a heading for a certain study has to do with that study, including all graphs, tables, figures, etc.

You’ve probably figured this out by now, but a science passage generally has a structure like this:

[Introductory Text]
Study One
[Text About Study One]
[Graph] [Table] [Equation]

Study Two
[Text About Study One]
[Graph] [Table] [Equation]

The information pertaining to each study doesn’t stop until the next study header appears. As much as this might seem like common sense, you’d be surprised how many points are lost due to forgetting this simple fact.

On every problem you read, underline the study, figure, or, table indicators. For example, anytime you read an indicator, such as “in study 1” or “in table 2,” etc., circle that indicator. Continually use markers to reduce the information you’re consuming; double-check that you’re looking at the right info.

For instance, if a problem asks: “In study three, which most likely explains the reduction in friction in trial two?” You don’t just want to narrow your vision to study three - you need to narrow it even further so that you’re only focusing on trial two.

You can’t go overboard with this strategy. The more you obsess over every particular label, study, figure, trial, slide, etc., repeat it to yourself, and double-check to make sure you’re looking at the right thing, the more accurate and quick you’ll be.

2. Wrong direction

If you’re getting tripped up on directional errors, you need to invest even more time to make sure that certain quantities are increasing or decreasing in the direction you’re expecting.

Often, my students don’t realize that a solid 50%+ of all their errors are purely directional. Once they come to this realization, they start investing the appropriate amount of attention in fixing the error. It’s not hard to avoid directional mistakes, but you need to be aware that you’re making them before you can fix them.

Not understanding a trend

A common Wrong Direction error is when you could not understand a trend. It is when students were not able to describe the relationship of the data. Increasing, decreasing, direct, indirect? Here is an EXAMPLE of an interpreting trends question:

Example 1

Researchers calculated the average G. firtis beak depth for each of the 10 years. The researchers noted that, during the 10-year period, 3 years eere exceptionally dry, and 1 year was very wet (See Figure 3). Small seeds are abundant during wet years. During dry years, all seeds are less abundant, and the average size of the available seeds is larger.

Example 1

During which of the following years were small seeds likely most abundant on Island B?
H. 1977
I. 1980
J. 1982
K. 1984

Solution: Answering this question requires understanding what caused small seeds or large seeds to be more abundant. In this case, this graph below and the two sentences directly above it provide the information you need. If you misread the graph or mixed up these sentences, you may have gotten the answer wrong. According to the two sentences, small seeds are abundant during the wet years. According to the graph, 1984 was a wet year, so D. 1984 is the correct answer.

3. Wrong “because“

While these questions are a bit rarer, they come up in quite a few ACT science passages. You know the type I’m talking about:

Does Table 2 indicate that the plankton in the East Indian Ocean Basin is dying off?
A. Yes - Because the water is getting warmer
B. Yes - Because the CO2 levels in the water are getting higher
C. No - Because the water is getting colder
D. No - Because the CO2 levels in the water are getting lower

If you got even one of these problems wrong, then just do the following:

  1. Read the problem
  2. Answer the Yes and No first without looking at the reasons
  3. Eliminate the two answer choices that don’t match your “yes or no” answer
  4. Eliminate the third answer choice because its reasons does not match with the directional clues of the question or the information in the passage
  5. Finally, be sure that the answer choice you select makes sense

For EXAMPLE, Does study 2 indicate that tigers are endangered within the Indian subcontinent?

You should first look at the answer choices:
A. Yes - because tiger death rates are outmatching tiger birth rates
B. Yes - because tiger hunting rates are increasing across the board
C. No - because tiger death rates are staying stagnant
D. No - because tiger death rates are matching tiger birth rates

You realize that the answer choice has to do with birth rates, death rates, or hunting rates. A table in study 2 indicates that death rates, year over year, are increasing by about 20%, while birth rates are decreasing by 20%, and hunting rates are increasing by 5%.

You come up with your own answer: Yes - they are endangered, because lots are dying more often, and less baby tigers are being born. Then, you go in and eliminate C and D.

Finally, look at A and B. Your initial instinct was to indicate that yes, tigers are endangered, largely and mostly because they aren’t being born as quickly as they’re dying. Does hunting have something to do with this?

Probably - but it isn’t the main reason why you selected your answer! That being the case, eliminate answer choice B - it’s not what you said. The correcr answer would be A.

This strategy, you’ll notice, is very close to the reading strategy that you’re already using. For “because” problems, the ACT reading strategy is pretty much an exact match for what you should be doing. Don’t get drugged by their deceptive answer possibilities!

4. Cannot be Determined

The “Cannot be determined” answer choice tends to distract students. When you see this as a possible answer choice, do not change your approach! Search for your directional cues; if you fail to find them, you can be confident choosing cannot be determined as the correct answer.

Example 2

Study 1
829 people were placed into four different groups: A, B, C and D. Each group was given the same task to complete in 60 minutes. The completion percentages of the four groups are shown in Figure 1.

Study 2
The same 829 people were shuffled into different groups and asked to repeat the task from Study 1. The results are tabulated below.

Example 2

1. According to Study 1, the greatest amount of people were assigned to which group?
A. Group B
B. Group C
C. Group D
D. Cannot be determined from the given information.

2. According to Study 2, the greatest amount of people were assigned to which group?
A. Cannot be determined from the given information.
B. Group B
C. Group C
D. Group D

3. Based on Studies 1 and 2, did completing the task a second time improve the completion percentages of the groups?
A. Yes; Completion percentages of Study 1 are higher than those of Study 2
B. Yes; Completion percentages of Study 2 are higher than those of Study 1
C. No; Completion percentages of Study 1 are higher than those of Study 2
D. No; The data is insufficient

4. Suppose the 829 people consisted of ages 17-23. Based on the passage, how would this information change the result, if at all?
A. The completion percentages would be higher
B. The completion percentages would be lower
C. The results of the study would not change
D. Cannot be determined from the given information


  1. D
  2. B
  3. B
  4. D

5. Didn’t know the random stupid science fact

In these problems, no matter how much time you spend on these problems, you’ll never be able to find the right evidence because it does not exist in the passage.

Of all the problem types that my students worry about, these are at the top of the list. How the heck are you expected to answer these random, annoying problems?

I understand the frustration. but there’s never more than two of these problems in any given science section. Sometimes, none show up at all. They’re rare - so they wont have a huge impact on your score.

Score Impact

We have included a chapter called “Outside Knowledge” that will hopefully cover the content from which such a question can from.However, if you really don’t know the trivial fact behind one of these problems, the only thing you can do is see that it’s a “pure knowledge” problem, find an answer, and move on to the next questions ASAP.
Remember: You either know the fact or you don’t. If you don’t, there’s no point in spending more than 1 second on these questions - just pick a random answer and move on!

There is one trick that will help: work by elimination rather than selection!!! You should already be doing this for every science problem, so this shouldn’t come as a surprise - but still, it’s very important to keep in mind.

For EXAMPLE, if you see a problem like this: Which of the following most likely leads to happiness or depression in the human brain?
A. Epidermis
B. Dopamine
C. Phosphorescence
D. Nucleoids

You might not know what any of these really mean, but you might have an idea. Use that idea to eliminate answers. “I know epidermis has something to do with skin. I think phosphorescence has to do with some sort of light, or fire, or something, and nucleoids is something to do with cells. So....I’ll go with B, even though I don’t know what it means. It’s the only thing that could have to do with your brain.” And so on and so forth.

So how do you know whether these problems are pure knowledge problems or not? How do you know when to cut and run? Not to provide seemingly oversimplified advice, but you’ll know them when you see them! If a problem:

  • Makes no reference to any studies, tables, or figures
  • Makes no reference to the passage whatsoever
  • Doesn’t contain the word “based on”
  • Doesn’t contain any of the terms or figures within the passage itself (based on a quick scan)
  • Starts with “which of the following”

Then it’s almost always a pure knowledge problem. As you keep studying, you’ll get better at recognizing them. Lets go through a solved example on a common topic that has a high probability of appearing: Water and Drying

Example 3

Before the salt mixtures were administered, a drying agent was placed in each tank and allowed to sit for two days. Then, 3 salt mixtures were made with water and stirred in separate tanks. Several properties were measured and the results organized in Table 1.

Example 3

1. Suppose an additional salt was tested that yielded a T value of 7.5 C. The relative humidity of this additional salt would most likely be closest to which of the following?
A. 15.5%
B. 16.3%
C. 17.6%
D. 18.8%

2. What was the purpose of allowing the mixtures to sit for two days before recording the results in Experiment 1?
A. To ensure the relative humidity of each salt mixture in each tank was constant
B. To ensure the temperature of each tank was constant
C. To remove any H20 present in the tanks
D. To remove any salts present in the tanks

3. In all 3 studies, the purpose of oven-drying the medium was to remove the:
A. Organic matter
B. Salts
C. Electrostatic force
D. Moisture

4. What was the most likely reason the scientist kept the wet soil in a heater, set to 105 C, for 1 hour before beginning the experiment?
A. To remove the moisture
B. To remove any organic matter in the soil
C. To ensure the soil was room temperature
D. To thoroughly clean the soil of unwanted contaminants


  1. D
  2. C
  3. D
  4. A

6. Wrong “inference”

Wrong inference problems are the second “most hated” ACT science problems because they seem like they’re based on opinion rather than in fact.

In reality, nothing could be further from the truth. Inference based Science problems are not answered by looking at the figures, tables, etc. It’s purely an inference problem. In other words, the problem is asking, what COULD be done to make something better, worse, etc.?

Note: Almost ALL inference problems have to do with experiment design. All inference problems have to do with hypothetical situations. In other words, you know you’re dealing with an inference problem if the problem is worded like so: “What thing, if it happened, would make something better or worse?”

Automatically, you know that this problem isn’t based on the facts in front of you - it’s based on scenarios you’ll need to imagine. You can also be pretty sure that it’s an inference problem if it has anything to do with the design of the study itself.

Other problems that should tip you off are:

  • The researchers are worried that the bees might not be collecting all the pollen laid out. What might help to ensure that the bees pick up all the pollen?
  • Scientist two wants to make sure that none of the radioactivity is leaking into the atmosphere. What could he do to ensure that this isn’t affecting the readings?
  • Which of the following is the biggest weakness in the current design of the study?

In all of these problems, you might be able to use the data and graphs etc. provided to help you, but the actual answer will exist only within the logical reasoning portion of your brain. Fortunately, all of these problems can be solved in the same simple way: reverse-engineer the question, answer on your own, and then eliminate the wrong answers one by one.

And now, for a change of pace, on to another error type that is based almost purely in fact.

7. Wrong Number

Of all ACT science errors, these are the most inexcusable - but also the easiest to fix. Many of the problems on the ACT science questions have numbers in their answers.

The only reason you’re getting these wrong is because you’re not filling in the proper “blanks.” In other words, there’s nothing “hard” about problems that require numbers of equations. They’re simply a different problem type, and they have nothing to do with your mathematical ability. You’re not allowed to use a calculator on this section, and the whole reason for that is that you don’t need one.

In all my years tutoring this exam, I’ve NEVER had a student get a problem like this wrong
and say that he or she doesn’t get how to do it. In EVERY case, my students simply made
silly mistakes. You can ONLY get these problems wrong if you MAKE MISTAKES.

How ridiculous will you feel if you realize that a certain equation is:
Volume = Pressure * Time.
Pressure = \(10^{-2}\)
Time = 500

Then say that the answer is 50,000, rather than 5, because you didn’t take the time to notice the negative sign in front of the exponent?

If you’re getting it wrong, it’s because you are not being careful. How do you get a problem like this wrong?

You either:

  1. Didn’t look at the figure, equation, or table carefully
  2. Didn’t take the time to figure out what the correct labels were
  3. Plugged in the wrong numbers.

If you got more than ONE “number” problem wrong on your ACT, you need to actively TRIPLE check these sorts of problems. It’ll be worth it - I promise.