Flashcards in Research Methods Deck (37):
Name 3 types of Experiments
> Lab experiment
> Field experiment
> Natural experiment
Describe a Lab Experiment
These are experiments carried out in a controlled setting. Lab experiments tend to demonstrate high internal validity and low external validity
Name 3 advantages of a Lab Experiment
> It is easily replicable, if the lab experiment is carried out successfully,it can be easily replicated to see if other researchers obtain similar results.
> In a Lab setting there is better control over variables. it is easier to control confounding variables than in other experiment settings, so high levels of precision can be achieved.
> Cause and effect can be easily established if all variables other than the IV are controlled.
Name 2 disadvantages of a Lab Experiment
> There is a loss of validity in lab experiments, due to establishing high levels of control, and narrowly defining IVs and Dvs , an experimental artificial and therefore recognizably different from real-life situations
> Demand characteristics occur when participants try to make sense of the research situation they find themselves in and adjust their behaviour accordingly. This leads to less reliable and accurate results.
Describe a Field Experiment
Field experiments are investigations carried out in a natural environment of those being studied (e.g. homes, schools, etc.) As with lab experiments, the researcher still manipulates an IV to produce a change in the DV, therefore causal relationships can be demonstrated.
Name 2 advantages of a Field Experiment
> Field experiments have improved ecological validity, by carrying out an experiment in a natural, real-life setting, the artificiality of the lab environment is avoided (i.e. reduced reliability and relation to real life)
> This type of investigation has a reduction of demand characteristics. Participants may be less conscious that they are taking part in a research study, so the likely influence of demand characteristics may be reduced.
Name 2 disadvantages of a Field Experiment
> It is difficult to establish high levels of control in a field experiment, not only control over IVs and in measuring DVs, but also over any potentially confounding variables
> Although realism is high in a field experiment, the results cannot be generalized to other real-life situations that differ from the one in which th field experiment took place
Describe a Natural Experiment
In a natural experiment, the researcher makes use of naturally occurring differences in the independent variable. This means that the researcher does not have direct control over the IV.
Name 2 advantages of Natural Experiments
> In Natural experiments there is a reduction of demand characteristics. Participants may be less conscious that they are taking part in an experiment, and so demand characteristics may be avoided.
> The experimenter does not intervene with the situation, al thought it is possible that the mere presence of the researcher may still produce an effect on the ppts behaviour
Name 2 disadvantages of Natural Experiments
> Loss of control is a disadvantage, since the investigator does not directly control the IV or assign participants to experimental conditions, the overall degree of control exercised than in a lab or field environment.
> The naturally occurring situation the observer is studying, may occur only rarely, thus reducing the available opportunities for research.
Describe a Correlational Analysis
Determining the extent of a relationship between two variables
Describe the use of Correlational coefficient
A number between -1 and +1 that tells us how closely the co-variables in a correlational analysis are related.
Describe a Natural observation
A research method carried out in a naturalistic setting in which the investigator does not interfere in any way, but merely observes the behaviour(s) in question.
Describe a Controlled observation
Participants are likley to know that they are under observation - behaviour is measured in a controlled setting. Similar to lab experiment, tight control of all variables (e.g. confounding). Lacks ecoloical validity due to social desirability bias created by being under observation.
Describe a Structured Observation
Behaviour category - dividing target behaviour into a subject of behaviours done by behavioural checklist.
Describe an Unstructured Observation
Record all relevant behaviours, there is no checklist/system.
Describe a Non-Participant Observation
Observational study whereby researcher does not join activity being observed
Describe a Participant Observation
Observer is also a participant is activity being studied.
Name the two types of Naturalistic Observation
Describe an Overt Naturalistic Observation
Researcher is open about their intentions in the field
Describe a Covert Naturalistic Observation
Researcher does not inform members of the group the reasons for their presence. True intentions are kept secret.
Name 3 types of Experimental designs
> Independent groups Design
> Repeated Measures Design
> Matched Pairs Design
Describe an Independent Groups Design
An experimental design where participants are allocated to two (or more) groups representing different experimental conditions
Name some advantages of an Independent Groups Design
There are no issues with order effects which occur when participants' performance is positively or negatively affected by taking part in two or more experimental conditions.
Name some disadvantages of an Independent Groups Design
There is the potential for error resulting from individual differences between the groups of participants taking part in the different conditions.
Describe a Repeated Measures Design
An experimental design which involves exposing every participant to each of the experimental conditions, so in effect participants are used as their own controls.
Name some advantages of a Repeated Measures Design
Individual differences between groups of participants are removed as a potential confounding variable. Also fewer participants are required, since data for all conditions collected are from the same group of participants.
Name some disadvantages of a Repeated Measures Design
Order effects may result when participants take part in more than one experimental condition. order effects can confound the results in two ways - either negatively through effects of fatigue or boredom, or positively through the effects of learning or practice
Describe a Matched Pairs Design
This design involves matching each participant in one of the experimental conditions as closely as possible with another participant in the second condition on all the variables considered to be relevant to performance in the study.
Name some advantages of a Matched Pairs Design
A matched pairs design combines the advantages of both an independent groups and repeated measures design.
Name some disadvantages of a Matched Pairs Design
Achieving Matched Pairs Design is both time consuming and difficult. Complete matching of participants on all variables can rarely be achieved.
Define Null Hypothesis
The Null Hypothesis predicts that the results of an experiment can be explained by chance variation alone rather than by the manipulation of the IV. For example in an experiment investigating the effect of a mnemonic on memory recall, the null hypothesis would predict no difference in the memory scores for the two conditions.
Define Directional Hypothesis
A Directional Hypothesis predicts the direction in which results are expected to occur
Define Non-Directional Hypothesis
A non-directional hypothesis predicts that there will be a difference between two conditions or two groups of participants, without stating the direction of the difference.
Define Random Sampling
A group of participants selected using a random technique so that every member of the target population has an equal chance of being selected.
Define Opportunity Sampling
A sample of participants produced by selecting people who are most easily available at the time of the study