PSYCHOLOGY Flashcards
Independent variable
The variable being altered by the experimenter.
Dependent variable
The variable being measured within the experiment.
Extraneous variable
An independent variable that can cause changes to the value of the dependent variable.
Confounding variable
Similar to extraneous variables, they change the value of the dependent variable systematically. If a confounding variable exists within an experiment, no valid conclusion is able to be drawn from the experiment.
Hypothesis
A clear statement predicting the effects of the independent variable on the value of the dependent variable.
Null hypothesis
States that a change in the independent variable will have no effect on the value of the dependent variable, any variation in results will be due to chance.
Alternative hypothesis
States a different relationship between the independent and dependent variables than was initially predicted.
Control group
This group is not exposed to the independent variable.
Experimental group
This group is exposed to the independent variable.
Convenience sampling
Makes use of people readily available, not representative of a wider population.
Random sampling
Each person within a population has equal chance of being selected, not necessarily representative of a wider population.
Stratified sampling
Attempts to eliminate confounding variables by making these variables evenly spread through the selected sample.
Qualitative data
Observations, opinions
Quantitative data
Numerical information/data, measurements
Subjective data
Based on opinion, no external criterion.
Objective data
Measured according to identifiable external criterion.
Repeated measures design
Everyone within the study participates in both experimental and controlled groups.
Counterbalancing
Participants are divided into two groups, with one under experimental conditions first, while the other is under controlled conditions first. These groups then swap. This design is used to eliminate confounding variables.
Matched participants design
Participants are matched up using key characteristics, eliminates confounding variables.
Independent groups design
Participants are randomly allocated to experimental and controlled groups.
Twin and adoption studies
Uses participants that are as naturally similar as possible.
Longitudinal design
The same participants are observed over different periods in their lives.
Cross-sectional design
Participants are different ages, cohorts etc. are observed at one point in time.
Sequential design
Attempts to eliminate limitations of both longitudinal and cross-sectional designs; a combination of both designs.