Ecological validity (Practical issues) Flashcards
What are ‘practical issues’?
The methodological choices researchers make when designing their research
What are the 3 practical issues in order of importance?
Type of experiment - lab or field
Supported by: Raine and Skinner
Sampling technique
Supported by: Milgram, Baddeley, and stratified sampling
Type of data - quantitative or qualitative
Supported by: Case studies like HM
Why do researchers have to think about the type of experiment? (2 points)
Laboratory experimental procedures have highly controlled extraneous variables - a causal relationship between an IV and an operationalised quantitative DV
Researchers have to decide whether to use a scientific, controlled laboratory study or an externally valid, real-life reflective field style study - not plausible to use both as they are dichotomous methodologies
How does Raine et al support the type of experiment being the most important practical issue? (4 points)
They conducted a standardised, controlled laboratory procedure to investigate brain functioning in NGRI vs non-murderers
Participants took part in a 32-minute CPT task following a 10-minute practice window
Operationalised DV with measurable units - no subjective interpretation
Matched pairs design prevented extraneous variables confounding the results - cause and effect could be established between brain functioning and those who pleaded guilty to NGRI
How does Skinner support the type of experiment being the most important practical issue? (4 points)
Skinner followed a standardised, controlled laboratory experimental procedure - high internal validity
He starved pigeons/rats to 75% of their well-fed weight and placed them in a cage with a food hopper that stopped for 5 seconds
Operationalised DV with measurable units - no subjective interpretation
This allowed cause and effect to be established between the behaviour presented (lever) and the cause (consequence, food reward)
How are Raine and Skinner limited in terms of practical issues? (3 points)
Both studies were set in artificial conditions which do not reflect the environment people experience daily
Raine:
Low task validity - the use of the CPT task of identifying targets is not reflective of the everyday brain activities of NGRI murderers
Skinner:
Low ecological validity - people rarely respond to antecedents, and receive consequences without other situational variables in complex social contexts
Why do researchers have to think about the sampling technique? (2 points)
Psychologists need to consider participant samples used in their studies to ensure they are representative of the wider population, particularly the generalisability of animals
The sampling method, be it random, opportunity etc will depend on the researcher’s access to the target population
How does Milgram support the importance of sampling techniques as a practical issue? (4 points)
Milgram studied the extent that someone would obey the orders of an authority
figure
He used volunteer sampling to get 40 male volunteers aged 20-50 by putting an advertisement in the newspaper
Volunteer sampling may produce biased results due to the Hawthorne effect - people have volunteered due to being interested in the topic so they give overly positive responses, leading to artificially high results
Cooperative volunteers may also show demand characteristics to “please or displease” the researcher depending on what they believe the aim of the study to be - reduced validity
How does Baddeley support the importance of sampling techniques as a practical issue? (3 points)
Most studies in psychology recruit Pps through an opportunity sample at a university, which is usually undergraduate students
Baddeley recruited 72 male and female psychology students from a university for this study
The conclusion that LTM encodes semantically is only representative of psychology undergraduates - likely culturally, socio-economically and cognitively different to the whole human population
How can psychologists sample populations effectively? (3 points)
Stratified sampling generates a more representative sample population
The target population is divided into subgroups (gender, age and ethnicity for example) and a proportionate number from each subgroup based on occurrence in the population is selected
There tends to be a lack of studies which adopt this sampling method due to time, cost constraints and inaccessibility to accurate demographic data
How is stratified sampling limited as a sampling technique? (2 points)
Idealistic but impractical - lack of access to demographic data combined with the impossibility of gaining an accurate measure of all the participant variables that apply to people
Participant samples should not be a primary practical issue to consider when deciding on the methodologies to use - generalisability issues are inevitable
Why do researchers have to think about the type of data they are collecting? (3 points)
Researchers need to decide whether they are going to explore a topic descriptively or test a hypothesis
This will in turn determine if they are going to collect quantitative data (numerical units) or qualitative data (descriptive words) to test their aims
Using quantitative data has benefits like objectivity, replication and scientific credibility - however, the depth of the human condition can be overlooked
How does the HM case study support the type of data collected being a practical issue? (3 points)
Suffered from anterograde amnesia
Gave huge insight into:
+ The transference of STM to LTM
+ The difference between declarative and non-declarative LTMs
Many experiments, interviews, and observations were conducted on him - they mostly produced qualitative data
What is the 1 strength and 2 weaknesses of case studies? (3 points)
Strength:
Qualitative methods can gather insight into thoughts and feelings which more quantitative methods can’t
Weakness:
+ Time-consuming and expensive
+ Researcher may lose their objectivity and elicit investigator effects due to the rapport and bond
What is the conclusion of your practical issues essay? (3 points)
The most important practical issues psychologists must consider in designing their research are:
+ Controlled lab studies V Ecologically valid snap-shot studies
+ Snap-shot quantitative data V Longitudinal qualitative data
The least important consideration is the sampling method as this will always be a methodological flaw
