Chapter 2

Question 1

Variables

Answer 1

• Factor that can vary and can be observed and controlled. Must have a clear definition.
• Random selection of participants reduces variability between groups. (individual differences)

Question 2

Experimental research

Answer 2

• You have control over the variables. (You can manipulate them)
• Can draw cause and effect conclusions
• However, could cause artificiality.

Question 3

Descriptive research

Answer 3

• Natural observations in real environments.
• Case studies, interviews, records, etc.
• Finds unique conditions that challenge current theories.
• However, could cause observer bias.

Question 4

Positive correlation

Answer 4

Variables are directly related to each other and move in the same direction. (Ex. height and weight.)

Question 5

Negative correlation

Answer 5

Variables are directly related to each other and move in different directions. (Ex. Hours of sleep and fatigue)

Question 6

Confounding variables

Answer 6

Change the strength in a theory. (social desirability, experimenter expectancy, placebo effect.)

Question 7

Histogram

Answer 7

Graph of frequency distribution.

Question 8

Mode

Answer 8

The most frequently occurring score in a distribution.

Question 9

Mean

Answer 9

Represents the average of a set of scores. Calculated by

Question 10

Median

Answer 10

Mid point of the data. Half of scores are above the median and half are below it. (unaffected by extreme scores)

Question 11

Variance

Answer 11

• Variability from the mean (average).
• The average of the squared deviation from the mean.

Question 12

Standard deviation

Answer 12

• Square root of the variance.
• A statistic that measures the dispersion of a dataset relative to its mean

Question 13

Normal distribution

Answer 13

Mode, mean and median are similar

Question 14

Skewness

Answer 14

• Mode, mean and median are different.
• If mean goes up to mode its negative direction.