2.2 Psychologists Use Descriptive, Correlational, and Experimental Research Designs to Understand Behavior

Question 1

research design

Answer 1

the specific method a researcher uses to collect, analyze, and interpret data

Question 2

Descriptive research

Answer 2

research designed to provide a snapshot of the current state of affairs

Question 3

Correlational research

Answer 3

research designed to discover relationships among variables and to allow the prediction of future events from present knowledge

Question 4

Experimental research

Answer 4

research in which initial equivalence among research participants in more than one group is created, followed by a manipulation of a given experience for these groups and a measurement of the influence of the manipulation

Question 5

case studies

Answer 5

descriptive records of one or more individual’s experiences and behavior

Question 6

survey

Answer 6

• a measure administered through either an interview or a written questionnaire to get a picture of the beliefs or behaviors of a sample of people of interest.
• The people chosen to participate in the research (known as the sample) are selected to be representative of all the people that the researcher wishes to know about (the population).

Question 7

naturalistic observation

Answer 7

research based on the observation of everyday events

Question 8

descriptive statistics

Answer 8

numbers that summarize the distribution of scores on a measured variable

Question 9

normal distribution

Answer 9

A data distribution that is shaped like a bell

Question 10

central tendency

Answer 10

the point in the distribution around which the data are centered

Question 11

dispersion

Answer 11

spread

Question 12

arithmetic mean

Answer 12

the most commonly used measure of central tendency

Question 13

median

Answer 13

• used as an alternative measure of central tendency when distributions are not symmetrical.
• the score in the center of the distribution, meaning that 50% of the scores are greater than the median and 50% of the scores are less than the median

Question 14

mode

Answer 14

represents the value that occurs most frequently in the distribution

Question 15

range

Answer 15

of the variable is the maximum observed score minus the minimum observed score

Question 16

standard deviation

Answer 16

symbolized as s, is the most commonly used measure of dispersion

Question 17

scatter plot

Answer 17

a visual image of the relationship between two variables

Question 18

Pearson correlation coefficient

Answer 18

• The most common statistical measure of the strength of linear relationships among variables
• value: ranges from r= –1.00 to r = +1.00

Question 19

Multiple regression

Answer 19

a statistical technique, based on correlation coefficients among variables, that allows predicting a single outcome variable from more than one predictor variable

Question 20

common-causal variable

Answer 20

a variable that is not part of the research hypothesis but that causes both the predictor and the outcome variable and thus produces the observed correlation between them

Question 21

spurious relationship

Answer 21

a relationship between two variables in which a common-causal variable produces and “explains away” the relationship

Question 22

independent variable

Answer 22

an experiment is the causing variable that is created (manipulated) by the experimenter

Question 23

dependent variable

Answer 23

an experiment is a measured variable that is expected to be influenced by the experimental manipulation