half psych
Variables - any factor that can change in amount or kind over time. Eg age, time, IQ, memory etc
An experiment tests the cause-effect relationship between variables
Independent variable – the variable that is systematically manipulated, changed or varied in some way by the experimenter, in order to assess its effect on participant’s responses (DV)
Dependent variable – the variable that the experimenter is measuring, shows any effects of the IV
It is called the DV because whether or not it will change and the way it will change depends on the effects of the IV
Research hypothesis – testable prediction about the relationship between two or more variables
Contains the IV and the DV and population about which the researcher intends to draw conclusions (IPAD)
The population is the entire group of research interest from which a sample is drawn; the sample is a subsection of the population who participate in the research
Eg “it is predicted that caffeine will improve the memory of adults.” Here the IV is caffeine , the DV is memory and the population is adults
Operationalized variables – are variables stated in terms that show how that variable is going to be measured in the experiment
Eg memory (dependent variable) could be operationalized as a score on a 40-item free recall test
Eg caffeine (independent variable) could be operationalised as 2 cups of Nescafe per day
NOTE in the unit ¾ psychology exam you will only be required to write a research hypothesis not operationalised hypothesis (this will actually lose your marks)
Extraneous variables – any variable other than the IV that MAY change the DV
These must be identified before the study is conducted so that they can be eliminated or controlled, in order for the researcher to conclude that the IV alone will cause a predictable change in the DV (rather than any other variables)
Confounding variable – any variable other than the IV that HAS caused a change in the DV
It is called a confounding variable
An experiment tests the cause-effect relationship between variables
Independent variable – the variable that is systematically manipulated, changed or varied in some way by the experimenter, in order to assess its effect on participant’s responses (DV)
Dependent variable – the variable that the experimenter is measuring, shows any effects of the IV
It is called the DV because whether or not it will change and the way it will change depends on the effects of the IV
Research hypothesis – testable prediction about the relationship between two or more variables
Contains the IV and the DV and population about which the researcher intends to draw conclusions (IPAD)
The population is the entire group of research interest from which a sample is drawn; the sample is a subsection of the population who participate in the research
Eg “it is predicted that caffeine will improve the memory of adults.” Here the IV is caffeine , the DV is memory and the population is adults
Operationalized variables – are variables stated in terms that show how that variable is going to be measured in the experiment
Eg memory (dependent variable) could be operationalized as a score on a 40-item free recall test
Eg caffeine (independent variable) could be operationalised as 2 cups of Nescafe per day
NOTE in the unit ¾ psychology exam you will only be required to write a research hypothesis not operationalised hypothesis (this will actually lose your marks)
Extraneous variables – any variable other than the IV that MAY change the DV
These must be identified before the study is conducted so that they can be eliminated or controlled, in order for the researcher to conclude that the IV alone will cause a predictable change in the DV (rather than any other variables)
Confounding variable – any variable other than the IV that HAS caused a change in the DV
It is called a confounding variable