Extraneous Variable - A variable, other than the IV, which may affect the DV
Confounding Variable - A variable, other than the IV which does affect the DV
Hypothesis
Alternative Hypothesis - States that there will be a relationship/effect between the IV and the DV
Null Hypothesis - States that there will be no relationship/effect between the IV and the DV
Directional/One tailed hypothesis - States that there will be a relationship/effect between the IV and the DV and states the direction
Non directional/two tailed hypothesis - States that there will be a relationship/effect between the IV and the DV, but doesn't state which direction
Types of Experiments
Lab - Controlled, usually artificial setting, researcher manipulates IV and measures DV
Field - Natural setting, researcher manipulates IV and measures DV
Natural - Researcher does not manipulate the IV (the change would be occurring regardless of whether or not the experiment was taking place) and measures the DV
Quasi - Researcher does not manipulate the IV but measures the DV, the IV is not present in everybody and therefore the researcher cannot use a random allocation of PP's
Evaluation of Experiments
Lab - (S) Highly scientific, high control over variables, easily to replicate
(W) Low mundane realism/ecological validity, risk of demand characteristics
Field - (S) Higher in mundane realism/ecological validity, lower risk of demand characteristics (W) Less control of extraneous variables so lower internal validity, potentially more expensive
Natural/Quasi - (S) Allows research into things where the IV cannot be manipulated for ethical or practical reasons, can study real life issues (W) Cannot establish cause and effect as the IV is not being directly manipulated
Evaluation of Experimental Design
Repeated Measures - (S) Fewer PP's are needed, (W) order effects, increased risk of demand characteristics
Independent Groups - (S) No order effects so reduced chance of demand characteristics, (W) requires more PP's and can't control PP variables
Matched Pairs - (S) Minimises the risk of extraneous variables, (W) Time consuming to match every PP's on variables,m
Counterbalancing and Random Allocation
Counterbalancing - Used to overcome order effects (RM) e.g ABBA Method - Every participant experiences both conditions but half do A then B and the other half do B then A
Random Allocation - Used to overcome issues with extraneous variables – put PP names in a hat and draw out the names so every other person goes in condition A
Sampling
Opportunity - Selecting the PP's who are the most convenient to you
Random - Every person in the same population that has the same chance of being selected
Stratified - The sample is representative of sub groups of the population
Systematic - Selecting every nth PP from sampling frame
Volunteer - Advertise for PP's in newspaper etc.
Evaluation of Sampling
Opportunity - (S) Less time consuming, (W) bias as PP's drawn from small % of the population
Random - (S) Unbiased, (W) Time consuming as you need a list of the whole population
Stratified - (S) Generalisable as it's proportionate to the population, (W) Time consuming
Systematic - (S) Unbiased due to objective system, (W) Time consuming
Volunteer - (S) No coercion, (W) Volunteer Bias
Ethical Issues
Informed Consent
Deception
Right to Withdraw
Protection from Harm
Confidentiality
Privacy
Observational Technique
Naturalistic - Carried out in an everyday setting where the investigator does not interfere in anyway
Controlled - Behaviour is observed under conditions where certain variables have been organised by the researcher
Overt - PP's are aware that their behaviour is being studied
Covert - PP's are unaware that their behaviour is being studied
Participant - Observations made by somebody who is participating in the activity being observed
Non - PP - Observations made by somebody who isn't participating in the activity being observed
Evaluation of Observational Techniques
Naturalistic - (S) High in ecological validity, (W) less control makes it harder to account for the reason for behaviour
Controlled - (S) Can focus on specific aspects of behaviour in replicable environments, (W) Lower in ecological validity
Overt - (S) Ethically sound, (W) Hawthorne Effect as PP's know that they're being observed
Covert - Behaviour is more likely to be genuine as PP's don't know that they're being observed, higher in external validity, (W) Ethical issues such as privacy/deception
Evaluation of Observational Techniques pt.2
PP - (S) Researchers can experience the phenomenon first hand, (W) Might not remember everything as it will be reported at a later date
Non PP - (S) More objective as the researcher is separate from the PP's, (W) Might not truly understand the the behaviour being studied
Evaluation of Self Report Techniques
Questionnaires - (S) Easier to distribute to large numbers, respondents might be more willing to disclose personal info, (W) Can only be done by those who can read and write, answers can't be clarified if not understood, acquiescence bias.
Structured - (S) Easily replicated, standardised - increased reliability, (W) No flexibility, can't follow up with PP if they say something interesting.
Unstructured - (S) Can follow up in detail on interesting points, (W) Harder to analyse, lacks objectivity, interviewer bias may occur.
Observational Design
Unstructured - Relevant behaviour is recorded but there is no system in place. Typically used in pilot studies
Structured - Systematic methods used to organise and record behaviour
Behavioural - Breaking up behaviour into operationalised variables that can be measured specifically, all behaviour must fit into a category and no behaviour should fit in more than one
Event - Counting the behaviour everytime that it occurs
Time - Recording whatever is happening e.g every two minutes
Self Report Design
Questionnaires - Open Questions - Invite different responses from different PP's – tends to produce qualitative data, Closed Questions - Have a predetermined range of responses – tends to produce quantitative data. There should be no ambiguity, leading, double negatives or double barrelled questions
Interviews - The interviewer should consider whether to write notes now or at a later date, consider non verbal communication e.g smiling or nodding, and ask appropriate questions
Content Analysis
An observational study in which behaviour is usually observed indirectly in visual, written or verbal material – information can be qualitative or quantitative
Qualitative - Looking for similarities which are turned into codes – rather than counting the number of appearances, quotes are used to demonstrate the code
Quantitative - Tallying the number of appearances of information in behavioural categories
Coding - The process of placing qualitative or quantitative data into categories
Content Analysis pt.2
Coding Evaluation - (S) High ecological validity, based on real life observations of existing content, easy to replicate / (W) different observers might interpret the information differently, risk of cultural bias in the observer
Thematic Analysis
Read and re-read the data thoroughly; no notes should be made
Break the data into meaningful units
Assign a code to each unit
Combine simple codes into larger categories
Check the emerging categories against a new set of data
Evaluation of Case Studies
Strengths:
Rich, in depth data / can study behaviour where ethically and practically an experiment wouldn't be possible
Weaknesses:
Low generalisability, problems of confidentiality and informed consent
Features of Science
Control - Controlling variables in an experiment in order to establish cause and effect
Objectivity - Research should not be affecting by the expectations of the researcher or their personal opinions
Replicability - Repeating the study to compare results can see if the results are valid; scientists must record their procedures carefully
Empiricism - Information is gained through direct observation and experience
Features of Science pt.2
Theory Construction - Deduction – theory construction occurs at the beginning of the process after making observations / Induction – starts with observations of phenomena and then hypotheses are developed and tested which eventually leads to theory
Falsifiability - being able to prove a hypothesis wrong makes something scientific – scientific research should be able to be disconfirmed
Paradigm Shift - Through scientific revolution, scientific beliefs change; through disconfirming theories, everyone gradually moves to accept the same things
Improving Reliability
Inter - Observer Reliability - The extent to which there is agreement between two or more observers in observations, calculated as a correlation co-efficient. (If inter- observer reliability is low – behavioural categories need to be operationalised better or observers might need more training)
Test - Retest - Same test or interview is given to the same PP's on two occasions to see if the same results are obtained, scores are compared using correlation. (If the test-retest reliability is low – test might be ambiguous so needs rewording)
Improving Reliability pt.2
Experiments - Standardisation of experiments can help to ensure reliability and that every PP gets the same experience
Inferential Testing
Significance Level - The probability that the results occurred by chance, typically p<0.05 (0.01 for drug trials)
Type 1 Error - Researcher rejects a null hypothesis that is actually true
Type 2 Error - Researcher accepts a null hypothesis that is actually false
Evaluation of Qualitative / Quantitative Data
Qualitative - (S) In depth, can gain greater insight into behaviour/thoughts etc. (W) Harder and more time consuming to analyse
Quantitative - (S) Easy to analyse and draw conclusions from, (W) Can oversimplify reality and lacks depth
Skewed Distribution
Positive Skewed Distribution - Most of the scores are clustered to the left – there are a few extreme scores which have an effect on the mean – mean is higher than mode or median (happy whale)
Negative Skewed Distribution - Most of the scores are clustered to the right – there are more lower scores so the mean is lower than mode or median
Peer Review
Practice of using independent experts to assess the quality and validity of scientific research and academic reports
Strengths: Ensures the validity and reliability of studies
Weaknesses: Due to the competitive field, not all reviewers will be objective, File Drawer Problem - Studies which are not significant are less likely to be peer reviewed and published (inaccurate representation of studies)
Correlations
Positive - As one co - variable increases, so does the other
Negative - As one co - variable increases, the other one decreases
Coefficient - The product of statistical tests that measure the direction and strength of correlations – it is always a number between – 1 and +1. The sign indicates the direction and the number indicates the strength – the closer to 1, the stronger the relationship. (Ideally 0.8+)
Measures of Central Tendency
Median - Middle number when in order
Mean - Add all numbers up then divide by the amount of numbers
Mode - The most common number
Measures of Dispersion
Range - Biggest number take away the smallest
Standard Deviation - Shows to what extent the values in a data set deviate from the mean. It is calculated using all of the values, and so is arguably more representative than the range.
Stats Test
Table
Sign Test
Work out the difference between the two sets of data
Add up the amount positive and negative differences, ignore PP's which have no difference (e.g + = 5, - = 3)
The less frequent sign is your S Value (e.g 3)
Work out the N Value, which is the number of PP's not including the 0 values
Compare your calculated value (S) to the critical value, found in the table