Research Methods Flashcards
what are the two different types of hypothesis and explain them
- null hypothesis: have no difference or correlation, idea that the IV will not effect the DV (e.g ‘there will be no difference’)
- alternative hypothesis: show a difference or correlation, included IV and DV where both are operationalised involving how each variable is to be manipulated (IV) and measured (DV)
what are the two different types of alternative hypothesis and explain them
-directional: a relationship/direction is shown (better/worse), tends to be used when there has already been a range of research carried out relating to the researcher’s investigation
- non-directional: states there is a correlation or direction but doesn’t specify
what is an independent variable
something the researcher changes or manipulates to observe effects . It is generally the cause of effect, has an effect on the DV
what is a dependant variable
something that is measured to see if there is any change. Generally described as the outcome/effect. The IV is a cause that has an effect on the DV
- must be measured using quantitative data
what does the term operationalisation mean
when the researcher clearly defines the variables in terms of how they are being measured. (more specific)
what is an extraneous variable
a variable that can effect the dependant variable unless it’s controlled. These are factors that can affect the results of the experiment
- e.g time of day- some ppts may be ‘morning ppl’ so more alert compared to others
- temperature- too hot/cold may affect ppt performance on task
- if extraneous variables are not controlled they can become confounding variables
what is a cofounding variable
a variable that has an effect on the DV. Unlike the extraneous variable, confounding variables do change systematically with the IV, e.g if time is too early, ppts won’t be fully concentrated as they r too sleepy
what are demand characteristics
- cues from the procedure that suggest what the research is about, therefore ppts change behaviour accordingly
- guess the aim of the study
what is the investigator effects
- any unwanted influence from the investigator on the research outcome e.g bias to some ppts, or only picking extraverts
- researchers presence/behaviour interferes with research
- e,g age/gender could influence how ppts interact with them
what does the term standardisation mean
- identical procedure set up in an experiment
- allows research to be replicated, in turn makes it reliable
- e.g standardised instructions, briefing, debriefing, timings and materials
- a way of controlling extraneous variables by keeping them the same across both conditions
define the term randomisation
- use of chance wherever possible to reduce the researcher’s influence on the design of the investigation
- ppt allocation random, selecting names out of a hat, using random name generator
what is a repeated measures design
- the same ppts take part in each condition
- they take part in ALL conditions of the IV
what is an independent measures design
- ppts are randomly allocated into different conditions and only participate in that condition
- may take names out a hat or use a name generator to assign ppts to each condition
what is matched pairs design
- ppts are paired together based on characteristics/variables relevant to the experiment and then each pair is allocated to one of the conditions. (each partner does a different condition)
- matched pairs are randomly allocated to one condition each
- often MZ twins are used in matched pairs design as they create perfect matched pair
what are the strengths of a repeated measures design
- differences can’t be due to individual differences as the same ppts take part in both conditions, act as their own control group, increasing internal validity
- less time is spent recruiting ppts (time efficient)
- researchers are saving money as less ppts are needed
what are the limitations of a repeated measures design
- ppts may perform worse on 2nd condition due to boredom (order effect), researcher cannot be confident that the IV has affected the DV or that the results were due to other factors
- ppts may do better in 2nd condition due to practise effects
- demand characteristics - guess aim and change behaviour accordingly
to reduce weaknesses: task may need to be changed between conditions to reduce extraneous variables
what are the strengths of an independent group designing
- only participate in 1 condition so there will be no order effect or practise effects, won’t become bored or overly practised at the task
- tasks won’t need to be changed, allows control between both conditions
-ppts are less likely to guess the aim, eliminating demand characteristics
what are the limitations of an independent group design
- differences could be due to individual differences, e.g more ppts with a particular characteristic are all randomly allocated to one condition then this presents an unfair playing field
- more ppts need to be recruited, time and cost ineffective
- to reduce weakness: random allocation can help reduce ppts variables
what are the strengths of matched pair design
- no order effects or practise effects
- tasks won’t need to be changed
- ppts variables are accounted for as ppts are matched
- ppts are less likely to guess the aim of study, eliminating demand characteristics
what are the limitations of matched pairs design
- matching ppts can be time consuming and expensive, need to identify key variables and measure them
- can be difficult to know which variables ppts should be matched on
define a laboratory experiment
- researcher controls environmental factors such as noise/temperature (possible extraneous variables) so the effects of the IV upon the DV can be observed and measured
- use standardised procedures to ensure replicability and reliability
what are the strengths and weaknesses of a lab experiment
strengths:
- highly controlled over confounding variables
- easier to establish cause and effect relationships, high internal validity
-highly replicable, standardised procedure
weaknesses:
- demand characteristics, ppts aware they are taking part in study
- low ecological validity- tasks aren’t reflective of everyday, artificial tasks
define a field experiment
- carried out in natural environment- real life setting, researcher directly manipulates IV
- have less control over extraneous variables
what are the strengths and weaknesses of a field experiment
strengths:
- less chance of demand characteristics, increasing validity
- higher ecological validity, degree of artificiality is reduced
weaknesses:
-difficult to replicate
-no control over extraneous or confounding variables, reliability is reduced
- not ethical, lack of consent and deception