Definitions Flashcards
What is a hypothesis?
A precise, testable statement about the predictable outcome of an investigation.
What is a null hypothesis?
A hypothesis based on the assumption that there is no difference between two conditions or no relationship between two variables (and that any difference would be coincidence).
What is a directional hypothesis?
A prediction which states the direction of the difference between two variables or which states the direction of any correlation.
What is a non-directional hypothesis?
A prediction which states there will be a difference/correlation between two variables/conditions, but does not state which direction.
What is an extraneous variable?
Any variable which may affect the dependant variable, OTHER THAN the independent variable.
What is a confounding variable?
One which varies systematically with the independent variable to alter the dependant variable. This causes us to falsely accuse the independent variable of causing the change with the dependant variable.
What is an operational variable?
The process of devising a clear way of measuring something, so another person knows exactly what you have done.
What are the three experimental designs, and what are the advantages and disadvantages?
INDEPENDENT GROUPS (unrelated design)- different participants for each condition of the IV. 😊 - no order effects 😔 - participant differences, and the requirement for more participants. REPEATED MEASURES (related design)- where each participant does both conditions of the IV. 😊 - controls participant differences and fewer participants required. 😔 - there is a need for two sets of equipment and there may be order effects (practice or fatigue). MATCHED PAIRS (related design)- where each participant does one condition, but are matched to the person doing the opposite condition (eg, in terms of intelligence). 😊 - no order effects, control over extraneous variables and no need for two sets of equipment. 😔 - it is impractical to match people at the beginning of an experiment and there may be other extraneous variables which cannot be tested by the investigator.
What is counterbalancing?
Half the participants do conditions in one order, and the other do them in the opposite order.
What is the difference between en experimental method and an experimental design?
EXPERIMENTAL METHOD - lab, field, natural and quasi.
EXPERIMENTAL DESIGN - how participants are allocated (ie, independent groups, repeated measures or matched pairs)
What is a true experiment?
One in which the researcher has manipulated the independent variable and measured the effect of dependant variable.
What are the three types of experimental methods?
LABORATORY - an experiment conducted in a controlled environment where the participants are usually aware they are taking part in an experiment.
FIELD - conducted in a real world where there is less control over extraneous variables. It is less likely that participants know they are part of an experiment.
What is an aim?
A statement about the purpose of an investigation.
What is a pilot study?
A small scale trial run done before the main study to identify problems or confusions and to correct these. The results of these studies are not included in the final analysis.
What is reliability?
Consistency
