Types of experiment (Paper 2) Flashcards
(26 cards)
What are laboratory experiments related with
high levels of control - the researcher has control over all the variables in the study.
What is used to control environmental factors e.g. noise and temperature in lab experiments
Standardised Procedures
How is the IV manipulated in a lab experiment
(IV) is changed (manipulated) by the researcher between the conditions of the experiment.
What happens to the DV in lab experiments
Any change in the dependant variable (DV) will be measured while all other possible variables that could change the DV are kept consistent between conditions.
Give a strength of lab experiments
By holding all variables outside of the IV and DV consistent researchers can be confidant in establishing a cause and effect relationship between changes/manipulations in the IV and the observed difference in the DV.
High internal validity, meaning observed change in DV is due to change in IV.
Lab studies are easily replicated due to the use of standardised procedures.
Give a weakness of lab experiments
Lab studies can lack ecological validity, a type of external validity. This means findings from a lab study cannot be applied to a range of real-world situations
Tasks conducted in lab studies often don’t reflect the kind of tasks performed in real-world situations (they lack mundane realism) lowering external validity
Participants are aware they are in a study, they may alter their behaviour due to demand characteristics, changing behaviour to match the aim.
What are field experiments related with
Naturalistic settings. This change in location is an attempt to avoid the artificial nature of lab studies.
How is the IV manipulated in field experiments
(IV) is still changed by the researcher between the conditions of the experiment
What happens to DV in field experiments
researcher measures the difference in the dependant variable (DV)
Give a strength of field experiments
Participants should behave more naturally in their normal environment, making it more likely any behaviour observed in the field experiment can be applied to other naturalistic settings. (higher ecological validity)
Tasks used in field experiments are more likely to have mundane realism, so be closer to the type of activities that the participant usually carries out.
If participants are unaware they are in an experiment participants will not show demand characteristics.
Give a weakness of field experiments
Field studies lack control over possible extraneous variables that could be influencing the measurement of the dependant variable.
In many field studies, it is difficult or impossible to randomly assign participants to separate conditions, resulting in a change in DV that may be due to participant variables, reducing internal validity.
What are natural experiments related with
The two levels of independent variables have (or will) occurred naturally (in the real world) without the influence of the researcher.
How is the IV manipulated in natural experiments
(IV) is NOT changed by the researcher between the conditions of the experiment
What happens to DV in natural experiments
Changes in the (DV) are still measured but other possible variables that could change the DV cannot be controlled.
Give a strength of natural experiments
Natural experiments allow research in areas that could not happen in controlled experimentation, either due to ethical or cost reasons.
High in external validity as natural experiments are an example of real behaviour occurring in the real world free of demand characteristics.
Give a weakness of natural experiments
As these events have already or will happen regardless of the researcher, they have no influence. This means extraneous variables can’t be controlled, so the researcher shouldn’t claim they have found a cause and effect relationship.
These are often very rare events that can’t be replicated exactly to test for reliability.
What are quasi experiments generally related to
Participants cannot be randomly assigned between levels of IV. Often because the level of IV is an innate characteristic of the participants. E.g. Gender, Age, Income level
How is the IV manipulated in quasi experiments
(IV) already exists in the participants so participants cant be randomised between the conditions of the experiment.
What happens to DV in quasi experiments
(DV) will be measured while all other possible variables that could change the DV are kept constant.
Give a strength of quasi experiments
Quasi-experiments are the only way to experimentally study factors that are pre-existing characteristics of participants
Give a weakness of quasi experiments
There may be other factors related to the level of IV that cannot be controlled for, these change systematically between the levels of IV and alter the measurement of the dependant variable. These are known as confounding variables.
What is a pilot study
A smaller version of a larger study that is conducted to prepare for that study and ‘iron out’ any problems
What is quantitative data
Data that can be counted, usually numbers
What is qualitative data
Data expressed in words and non –numerical
