Naming, selecting and interpreting quantitative research designs, including meta-analysis

Question 1

Cross-sectional

Answer 1

A cross-sectional study involves looking at people who differ on one key characteristic (the variable of interest) at one specific point in time. The data is collected at the same time from people who are similar in other characteristics but different in a key factor of interest such as age, income levels, or geographic location. Participants are usually separated into groups known as cohorts. For example, researchers might create cohorts of participants who are in their 20s, 30s, and 40s.

Question 2

Longitudinal

Answer 2

Longitudinal research is a type of correlational research that involves looking at variables over an extended period of time. This type of study can take place over a period of weeks, months, or even years

Question 3

Experimental

Answer 3

• Experimentation investigates cause-and-effect relationships
• Manipulate levels of IV(s) and observe the effect on DV(s)
• Random assignment across (between-participants) groups

Question 4

Meta-analysis

Answer 4

A meta-analysis is basically a study about studies. It is used to get an integrated result. In other words, a researcher reviews previously published studies on a topic, then analyzes the various results to find general trends across the studies. It is done systematically, follows certain inclusion criteria, contains a pool of results and is based on a quantitative analysis.

Question 5

Quasi-experiment

Answer 5

• Approximate characteristics of true experiments
• What’s missing is random assignment
• Used when variable of interest cannot be manipulated
• Used when a naturally occurring variable is used to create comparison groups:
o PP variable: comparisons between PP types
 E.g. male v female, old vs. young

Question 6

Single-case

Answer 6

Small sample and single case designs are based on an idiographic approach (The intensive study of a single person or small number of people)
• The focus is on studying the individual characteristics of the person in depth
• Can be contrasted with a nomothetic approach (A focus on general processes across a larger group of people)

Question 7

ABA design

Answer 7

The most basic single-subject research design is the reversal design, also called the ABA design. During the first phase, A, a baseline is established for the dependent variable. This is the level of responding before any treatment is introduced, and therefore the baseline phase is a kind of control condition. When steady state responding is reached, phase B begins as the researcher introduces the treatment. There may be a period of adjustment to the treatment during which the behaviour of interest becomes more variable and begins to increase or decrease. Again, the researcher waits until that dependent variable reaches a steady state so that it is clear whether and how much it has changed. Finally, the researcher removes the treatment and again waits until the dependent variable reaches a steady state.
If the dependent variable changes with the introduction of the treatment and then changes back with the removal of the treatment (assuming that the treatment does not create a permanent effect), it is much clearer that the treatment (and removal of the treatment) is the cause. In other words, the reversal of behaviour greatly increases the internal validity of the study.