Research methods Flashcards
define experimental method
involves manipulation of an IV to measure the effect of the DV. Experiments may be laboratory, field, natural or quasi
define aim
A general statement of what the researcher intends to investigate, the purpose of the study
define hypothesis
A clear, precise, testable statement that states the relationship between the variables to be investigated. Stated at the outset of any study
define directional hypothesis
states the direction of the difference or relationships (one tailed)
previous research available and reliable
define non directional hypothesis
does not state direction of the difference or relationships
no previous research available
define operationalisation
Clearly defining variables in terms of how they can be measured
define extraneous variable
any variable other than the IV that may affect the DV if not controlled. nuisance variables that do not vary systematically with the IV
define Confounding variables
A kind of EV but the key feature is that it varies systematically with the IV. Therefore we cannot tell if changes in the DV are due to the IV or the CV.
define Demand characteristics
any cue from the researcher/research situation that may be interpreted by the ppts as revealing the purpose of an investigation .This may lead to a participant to change their behaviour within the research situtaion
define investigator effect
any effect of the investigators behaviour (conscious or unconscious) on the research outcome (DV). This may include everything from the design of the study to the selection of, and interaction with participants during the research process
define randomisation.
the use of chance methods to control for the effects of bias when deciding the order of experimental conditions
define matched pair design
pairs of ppts are first matched on some variables that may affect the DV. Then one member of the pair is assigned to condition A and the other to condition B
define standardisation
using exactly the same formalised procedure and instructions for all the participants in a research study
define experimental design
the different ways in which participants can be organised in relation to the experimental conditions
define independent group designs
ppts are allocated to different groups where each group represents one experimental condition
define repeated measures
all participants take part in all conditions of the experiment
define random allocation
an attempt to control for participant variables in an independent group design which ensures each participant has the same chance of being in one condition as the other
define counter balancing
an attempt to control for the effects of order in a repeated measures design: half the ppts experience the condition in one order and the other half in the opposite order
define a lab experiment
conducted in highly controlled settings/environment (not only in a lab.) IV in manipulated to see the effect on the DV
define A field experiment
IV is manipulated to see the effect on the DV, This occurs in a natural setting/every day sitution
define a natural experiment
eg. earthquakes
The IV id not manipulated by the researcher but would have occurred anyway. The IV is naturally occurring and the DV is measured.
define a Quasi experiment
IV is not manipulated by the researcher, instead it is based on existing differences between people to see the effect on the DV.
–> also highly controlled like the lab
—> eg. age/gender/ethnicity
Strengths and limitations of Lab experiments
S-
EVs and CVs can be controlled
high internal validity
can easily be replicated
L-
May lack generalisability/low external validity
low mundane realism/low ecological validity
Demand characteristics-> ppts may guess the purpose of the study
Strengths and limitations of field experiments
S-
natural environment/ high mundane realism
ppts don’t know they are part of the investigation therefore low risk of demand characteristics
L-
Natural event may only occur rarely
Participants are not allocated randomly–> difficult to generalise
Strengths and limitations of Natural experiments
S-
sometimes only way to carry out an ethical investigation
great external validity
L.
Lack of mundane realism+ demand characteristics if conducted in a lab.
participants are not randomly allocated- findings may not be generalisable
these events rarely occur
strengths and limitations of Quasi experiments
S- high control
comparisons can be made between people
L- people cannot be randomly allocated therefore there may be CVs
Iv is not deliberately changed by the researcher therefore, we cannot be sure if it is the thing affecting the DV
describe what happens during briefing
this occurs before the study. The researcher informs the ppts about some or all of the aims, what they will be asked to do, their rights and whether they want to participate.
describe what happens during debriefing
occurs at the end of a study. This is important if deception has been used. Participants should be informed about the true nature of the study and must give their consent for their data to be used
name some examples of sampling techniques
random, stratified, opportunity, volunteer, systematic
Describe stratified sampling
- researcher calculates proportion of ppts needed to mirror the target population-
researcher stratifies the population into a sampling frame to represent different subgroups within the target - all names go into a random generator
- select names until they have the desired number of ppts
the composition of the sample reflects the proportions of people in certain subgroups (strata) within the target population or wider population.
define opportunity sample
researchers selecting anyone that seems to be willing and available
define volunteer sample
participants selecting themselves to be part of the sample (self selection)
define systematic sampling
researchers select ppts in a systematic way from the target population.
- produce a sampling frame- a list of people in the target population organised in a particular way (eg. alphabetical order)
2.choose sampling system (eg. every 3rd person)
3.work through sampling frame until it is complete
define random sampling
when all members of the target population have an equal chance of being selected
eg. lottery method.
Strengths and Limitations of Random sampling
strengths
+unbiased-extraneous and confounding variables equally divided between groups increasing internal validity
Limitations
-Time consuming
-expensive
-selected participants may not agree to participate (it becomes more of a volunteer sample)