3 data structures

data structure 1

One Group with One or More Separate Variables Measured for Each Individual (Gravetter et al., 2020)

• one (or more) variables measured per individual

• variable/s is/are described by descriptive statistics

• may use category and/or numerical variables

descriptive research

involves measuring one or more separate variables for each individual with the intent of simply describing the individual variables

survey research

a useful way of obtaining data about people’s opinions, attitudes, preferences, and experiences that are hard to observe directly; data may be obtained using questionnaires and interviews.

relationship between variables

two (or more) variables observed and measured; one of two possible data structures used to determine what type of relationship exists

data structure 2

One group with two variables measure for each individual

• one group of respondents (subject)

• measurement of two variables for each respondent

• goal is to describe the type and magnitude of the relationship

• patterns in the data reveal relationships

• non-experimental method of study

correlational method

two different variables are observed to determine whether there is a relationship between them

correlational method limitations

• can demonstrate the existence of a relationship

• does not provide an explanation for the relationship

• most importantly, does not demonstrate a cause-and-effect relationship between two variables

data structure 3

comparing two or more groups of score

• one variable defines the group

• scores are measure on second variable

• both experimental and non-experimental studies use this structure

experimental method

• in this research design, one (or more) variable is manipulated while another variable is observed or measured

• this design aims to establish a cause-and-effect relationship between the two variables and attempts to control all other variables to prevent them from influencing the results

independent variable

sometimes referred to as explanatory variable is the variable (antecedent condition) that the experimenter intentionally manipulates

dependent variable

• sometimes referred to as outcome variable, is the behavior being observed or measured by the experimenter

• the specific behavior that a researcher tries that is measured

experimental condition

a condition in an experiment wherein the subjects will receive the experimental treatment

control condition

a condition in an experiment wherein the subjects do not receive the experimental treatment

quasi-experimental design

often seem like (as the prefix quasi implies) real experiments, but they lack one or more of its essential elements, such as manipulation of antecedents and random assignment to treatment conditions

pretest/posttest design

a research design used to assess whether the occurrence of an event alters behavior; scores from measurements made before and after the event (called the pretest and posttest are compared)

nonequivalent groups design

a research design used to compare the effects of different treatment conditions on pre-existing groups of subjects; random assignment is not possible in this design

ex-post facto study

also known as Causal-Comparative Design, is a study in which a researcher systematically examines the effects of pre- existing subject characteristics (or subject variables) by forming groups based on these naturally occurring differences between subjects

longitudinal design

a method in which the same group of subjects is followed and measured at different points in time; a method that looks for changes across time