### All AP Psychology Resources

## Example Questions

### Example Question #111 : History And Research

What kind of statistical test would be used to determine if there is a linear relationship between two variables?

**Possible Answers:**

Chi-square

Pearson correlation

ANOVA

T-test

Average

**Correct answer:**

Pearson correlation

A Pearson correlation between two variables indicates that as one variable increases, another variable either increases or decreases by some amount in a linear manner.

### Example Question #1 : Interpreting Results

A study finds a strong negative correlation between the amount of chocolate a child consumes and the number of absences the child has from school. Which of the following values could express that correlation?

**Possible Answers:**

**Correct answer:**

Correlations range between and , with signifying the strongest possible negative correlation between two variables, signifying the strongest possible positive correlation, and signifying the complete absence of any correlation between two variables.

### Example Question #1 : Interpreting Results

What is an illusory correlation?

**Possible Answers:**

An illusion of a correlation (often called sans-stats)

A perfect correlation between two variables

The perception of a relationship where none exists

A type of Pearson product moment correlation commonly used in the field of social psychology

When one variable negatively predicts a second variable

**Correct answer:**

The perception of a relationship where none exists

An illusory correlation occurs when someone thinks that two variables are related, but they are actually not (they have a correlation of 0).

### Example Question #1 : Interpreting Results

Which of these represents the strongest correlation coefficient?

**Possible Answers:**

**Correct answer:**

Correlation coefficients range from -1 to 1, with the strongest correlations being closer to -1 or 1. A correlation of 0 indicates no relationship between two variables. Negative correlations can be as strong or stronger than positive correlations; the most important factor is the *magnitude* of the correlation.

### Example Question #1 : Interpreting Results

Which term refers to the middle term in a distribution of data?

**Possible Answers:**

The median

The mean

The standard deviation

The range

The mode

**Correct answer:**

The median

The median is the middle number in a data set. For example, the median of {3, 7, 4, 5, 8} is 5. The terms must first be placed in increasing order: {3, 4, 5, 7, 8}. From here, it becomes evident that 5 is the middle term, or median.

### Example Question #1 : Interpreting Results

Which of the following is an appropriate definition for statistics?

**Possible Answers:**

Numerical data that shows the cause of a certain phenomenon

The negative or positive correlational relationship between different percentages

A subjective interpretation of numerical data

An analysis of numerical data

None of these

**Correct answer:**

An analysis of numerical data

Statistics play a big role in much of the research in the field of psychology. In studying groups of people and individuals, their behaviors, reactions, etc. a researcher will have lots of numerical data on their hands. Statistics is the analysis of this numerical data.

### Example Question #2 : Interpreting Results

Carol did a study examining the link between male students' test scores and their alcohol consumption. Other researchers replicated her study in a similar setting and got back similar results, but argued that her study answers a different question than it was designed to answer.

Carol's study is __________.

**Possible Answers:**

Neither valid nor reliable

Reliable and valid

Valid, but not reliable

Reliable, but not valid

None of the other answers is correct

**Correct answer:**

Reliable, but not valid

A study's validity is its ability to scientifically measure the concepts it was designed to measure. A study's reliability** **is its ability to yield similar results when replicated in a similar setting.

Because Carol's study could be replicated but does not answer the question it was designed to answer her study is reliable, but not valid.

### Example Question #1 : Interpreting Results

In a correlation experiment which number shows the weakest correlation?

**Possible Answers:**

**Correct answer:**

The number describing two variables relationship is the correlation coefficient. This could show a positive correlation (+ number) or a negative correlation (- number). The further from 0 the coefficent is the stronger the correlation.

### Example Question #1 : Interpreting Results

When measuring central tendency, which of the following choices is known to be biased depending on the data set?

**Possible Answers:**

Standard deviation of the mode

Median

Mean

Standard deviation

Percent error

**Correct answer:**

Mean

The mean is the average of a data set. On the other hand, the median is considered to be the 50th percentile—that is cutting the entire data set in half and representing the exact middle of the data set. The mean may be skewed depending on the data set. For instance, the median may be 50 but because of a few higher numbers, the mean could be 56. Using the mean as a measure of central tendency may cause the distribution to be a bit lopsided. Percent error is a statistical measure of the marginal error of actual results compared to expected results; therefore, percent error would not be the correct answer. Additionally, standard deviation is the measurement of the deviation from a group as a whole. This calculation is often conducted using averages (means); thus, the options standard deviation and standard deviation of the mode would also be incorrect.

### Example Question #1 : Interpreting Results

A researcher has determined through an experiment that moderate doses of ginseng have no effect on verbal memory; thus, he fails to reject the null hypothesis. In reality, the researcher missed a critical data point in his analysis that should have pointed towards a positive effect of ginseng on memory. This is an example of which of the following types of research error?

**Possible Answers:**

Type II error

Type I error

Experimental drift

Lurking variables

Confounding variables

**Correct answer:**

Type II error

Type II error—also called a false negative—occurs when a researcher incorrectly fails to reject a false null hypothesis. In other words, the researcher should have rejected the null hypothesis in favor of the experimental hypothesis. In this case, the researcher should have found evidence in favor of the experimental hypothesis that ginseng consumption has a significant effect on memory; however, the researcher failed to do so because of some experimental error (i.e. random or systematic, the problem does not specify).

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