Chapter 1 - Research Methods In Psychology Flashcards
Independent Variable (IV)
Deliberately manipulated or varied some way by the experimenter. This is planned before the experiment begins.
Dependent Variable (DV)
The property that is measured in the research. Its value depends on the IV. The DV is therefore the property tat the researcher believes will change as a result of changes in the value of the IV.
Operationalisation
Operationalisation of a variable means that it is stated in terms hat show how it is measured. For example:
− Age: Operationalised as age in total months.
− IQ: Operationalised as the score on a 40-item multiple-choice test.
− Aggression: Operationalised as the number of aggressive responses in an observed 30-minute period.
Extraneous Variable
A variable other than (extraneous to) the IV that could cause changes in the value of the DV. Extraneous variables are undesirable. When the potential effects of an extraneous variable have been removed from the experiment, the variable is said to be a controlled variable.
Confounding Variable
A variable other than the IV that has a systematic effect on the value of the DV (t acts like a second, unwanted, IV). If a confounding variable exists, no valid conclusion can be drawn.
Population
The group about which we wish to draw conclusions is referred to as the population.
Sample
Refers to the members of the population that have been chosen to take part in the research.
Random Sampling
A sampling procedure in which every member of the population has an equal chance of being selected.
Placebo Effect
Refers to the participants’ behaviour being influenced by their expectations of how they should behave, caused by the belief that they have received some treatment.
Qualitative Data
Refers to the descriptions of the characteristics of what is being studied. In psychological research this could be:
− Emotional State: Happy/sad/angry, etc.
− Difficulty Of Task: Easy/moderate/difficult/very difficult
Quantitative Data
Refers to measurements: numerical information about the variables being studied. Most psychological testing aims to gather quantitative data because we can perform statistical procedures on these and, provided the data are accurate and precise, we can determine whether our results are significant and our hypothesis can be supported.
Subjective Data
Are based on opinion and there is no external yardstick by which they are measured.
Objective Data
Are measured according to an identifiable external criterion. Each person using an objective measure correctly will obtain the same result.
Reliability
Refers to the extent to which a measure could be expected to produce the same result with the same subjects under the same conditions on other occasions.
Validity
Refers to the extent to which an instrument measures what it is supposed to measure.