Individual Differences, Variability & Interpreting Tests

Question 1

What is the main focus of psychological measurement?

Answer 1

Identifying differences between people in behavior and psychological characteristics.

Question 2

What are the two types of differences psychologists evaluate?

Answer 2

• Interindividual Differences (between-person differences)
• Intraindividual Differences (within-person differences)

Question 3

Define interindividual differences.

Answer 3

Differences that exist between different people.

Question 4

Define intraindividual differences.

Answer 4

Differences within the same people over time or under different circumstances.

Question 5

What is the importance of identifying individual differences in applied contexts?

Answer 5

Practitioners strive to identify how people vary to tailor interventions and understand psychological phenomena.

Question 6

What is the role of psychometrics in psychological measurement?

Answer 6

Psychometrics is dependent on accurately identifying individual differences through well-designed measurement processes.

Question 7

What does reliability in psychological testing refer to?

Answer 7

The consistency of test scores over multiple administrations.

Question 8

What does validity in psychological testing assess?

Answer 8

Whether differences in test scores reflect true differences in the same attribute.

Question 9

What statistical concept quantifies variability in a distribution of scores?

Answer 9

Variance.

Question 10

What is standard deviation?

Answer 10

The square root of the variance, reflecting the size of the raw deviation scores.

Question 11

What is the central tendency?

Answer 11

• Mean Score (Average)
• Mode (Most Scored)
• Median (Mid-point Score)

Question 12

How is the mean calculated?

Answer 12

Sum up the total scores and divide by the number of responses.

Question 13

What is a normal distribution?

Answer 13

A symmetrical distribution of scores around the mean.

Question 14

What is a positively skewed distribution?

Answer 14

A distribution with fewer scores above the mean, resulting in a skewness score greater than 0.

Question 15

What is a negatively skewed distribution?

Answer 15

A distribution with fewer scores below the mean, resulting in a skewness score below 0.

Question 16

What does covariance measure?

Answer 16

The degree to which two distributions of scores vary in a corresponding manner.

Question 17

What is correlation?

Answer 17

A measure of the strength and direction of the association between two variables.

Question 18

What does a scatterplot visually represent?

Answer 18

The association between two variables, with each dot representing a person’s score.

Question 19

What indicates a strong positive association in a scatterplot?

Answer 19

High scores in one variable coincide with high scores in another.

Question 20

What indicates a strong negative association in a scatterplot?

Answer 20

High scores in one variable coincide with low scores in another.

Question 21

Fill in the blank: Variance reflects the variability of the _______.

Answer 21

squared deviation scores.

Question 22

True or False: A high standard deviation indicates less variability in the distribution.

Answer 22

False.

Question 23

What are some key considerations for interpreting variability?

Answer 23

• Should always be positive (0 or above)
• No criteria to determine what is small or large variability
• Only compare measures scored using the same units

Question 24

What does a score represented by a dot in a scatterplot indicate?

Answer 24

The location of the dot is based on two different scores.

Question 25

What can a scatterplot help identify in data?

Answer 25

Extreme scores (outliers) and trends (upward or downward).

Question 26

What does an upward trend in a scatterplot indicate?

Answer 26

High scores in one variable coincide with high scores in another.

Question 27

What does a downward trend in a scatterplot indicate?

Answer 27

High scores in one variable coincide with low scores in another.

Question 28

What does no trend in a scatterplot signify?

Answer 28

No consistency (association) between the two variables.

Question 29

What is covariance?

Answer 29

Reflects the association between the variability of two distribution scores.

Question 30

How is covariance calculated?

Answer 30

Identify deviation from the mean in both variables, multiply deviation scores, and calculate mean of cross-products.

Question 31

What does a variance-covariance matrix display?

Answer 31

Variance of each variable on the diagonal and covariance between variables in the other cells.

Question 32

What is the simplest form of a variance-covariance matrix?

Answer 32

2 x 2 matrix including two variables.

Question 33

What does a correlation coefficient indicate?

Answer 33

Both the direction and magnitude of an association.

Question 34

What range do correlation coefficients typically fall within?

Answer 34

-1 to +1.

Question 35

What does a correlation value of 0 indicate?

Answer 35

No association between the two variables.

Question 36

What does a positive correlation value signify?

Answer 36

A positive association between the variables.

Question 37

What does a negative correlation value signify?

Answer 37

A negative association between the variables.

Question 38

What is the significance of correlation magnitude?

Answer 38

Indicates the strength of the association (effect size).

Question 39

What are the classifications of Pearson correlation values?

Answer 39

* .10 to .30 = small (low consistency) * .30 to .50 = medium (some consistency) * .50 to 1.00 = large (strong consistency)

Question 40

How are correlation coefficients typically represented?

Answer 40

By an r value.

Question 41

What is the purpose of a correlation matrix?

Answer 41

To present correlations between multiple variables.

Question 42

What is the raw score in the context of test scores?

Answer 42

The actual number obtained on a test.

Question 43

What are two facets to consider when interpreting a test score?

Answer 43

* The meaning of the raw score * The psychological implications of this score.

Question 44

What is a percentile rank?

Answer 44

Indicates the percentage of scores below a specific score.

Question 45

What are Z-scores used for?

Answer 45

To standardize scores by converting them into standard deviation units from the mean.

Question 46

What does a positive Z-score indicate?

Answer 46

The score is above the mean.

Question 47

What does a negative Z-score indicate?

Answer 47

The score is below the mean.

Question 48

What is the purpose of converting Z-scores into values that are easier to understand?

Answer 48

To help compare scores using a more relatable average.

Question 49

What is the significance of test norms?

Answer 49

They provide a reference score based on a representative sample.

Question 50

What is the importance of a reference sample in test development?

Answer 50

It helps provide norms for a test and ensures comparability.

Question 51

What does a person in the 90th percentile mean?

Answer 51

They scored higher than 90% of the people.

Question 52

What is a key question to consider regarding how to interpret scores?

Answer 52

Is the raw score above, below, or equal to the mean score?

Question 53

What can observed (raw) test scores rarely index?

Answer 53

The true amount of a psychological attribute.

Question 54

What is the purpose of normalised scores?

Answer 54

To help interpret individual scores relative to the average population.

Question 55

What transformation is conducted for non-normally distributed samples?

Answer 55

Normalised transformations.

Question 56

What do standard scores help identify?

Answer 56

The degree scores are above or below the mean level.