AS Level Flashcards
Operationalised hypothesis
Clearly defined and measurable statement
Directional hypothesis
States whether changes are greater or lesser, positive or negative
Non-directional hypothesis
Doesn’t state the direction, just that there’s a difference or correlation
When is a non-directional hypothesis used?
When there’s no theory or previous research
Research issues: Extraneous Variables
Are nuisance variables that have the potential to affect the results and may make it difficult to detect an effect.
A researcher may control these
:Research Issues: Confounding variables
Change systematically with the IV so we can’t be sure if any observed change in the DV is due to the CV or IV.
Research Issues: Demand characteristics
Any cue from the researcher or research situation that may reveal the aim of the study and change participants’ behaviour
Research issues: Investigator effects
Any effect if the investigator’s behaviour on the outcome of the research (the DV) and also on design decisions
Research issues: Randomisation
The use of chance when designing investigations to control for the effects of bias
Research issues: Standardisation
Using the same formalised procedures for all participants in a research study.
Differences become EVs otherwise
Pilot studies & more: Pilot Studies
Small scale trial run of an investigation to pre-test procedures so that research design can be modified if required
Pilot studies aren’t restricted just to experimental studies
Pilot studies & more: Single Blind Procedure
Participants don’t know the aims of the study so demand characteristics are reduced
Pilot studies & more: Double-blind procedure
Both the participant and the researcher don’t know the aims of the study to reduce demand characteristics
Pilot studies & more: Control groups and conditions
Control groups (independent measures) or control conditions (repeated measures) are used to set up a comparison.
They act as a baseline and help establish causation
Experimental designs: independent groups
One group does condition A and a second group does condition B.
Participants should be randomly allocated to experimental groups.
Independent groups: Positives + explanations
-No order effects: participants are only tested once so can’t practise or become bored/tired. This controls an important CV
-Won’t guess the aim: participants are only tested once so are unlikely to guess the aims. Therefore, behaviour may be more natural (higher realism)
Independent groups: Negatives + Explanations
-Participant Variables: the participants in the two groups are different, acting as the EV/CV. This may reduce the validity of the study
-Less Economical: need twice as many participants as repeated measures for the same data. This means more time is spent recruiting which is expensive
Experimental designs: Repeated Measures
Same participants take part in all conditions of an experiment. The order of conditions should be counterbalanced to avoid order effects
Repeated Measures: Positives + Explanations
-Participant variables: the person in both conditions has the same characteristics. This controls an important CV
-Fewer Participants: half the number of participants is needed than in independent groups. This means less time is spent recruiting participants
Repeated measures: Negatives + explanations
-Order effects are a problem: participants may do better or worse when doing a similar taste twice and there are also practice/fatigue effects. This reduces the validity of results
-Participants guess aims: participants may change their behaviour which may reduce the validity of results
Experimental designs: Matched pairs
Two groups of participants are used but they’re also related to each other by being paired on participant variables that matter for the experiment
Matched pairs: Positives + Explanations
-Participant variables: participants matched on a variable that’s relevant to the experiment. This controls participant variables and enhances the validity of the results
-No order effects: participants are only tested once so no practice or fatigue effects which also enhances the validity of results
Matched Pairs: Negatives + Explanations
-Matching isn’t perfect: Matching is time consuming and can’t control all relevant variables meaning not all participant variables can be addressed
-More participants: Need twice as many participants as repeated measures for the same data. This means more time is spent recruiting which is expensive
Types of experiment: Lab Experiment
A controlled environment where extraneous and confounding variables can be regulated. Participants go to the researcher. The independent variable is manipulated by the researcher and effect on the dependent variable is recorded.
Lab experiment: Positives + Explanations
-EVs+CVs can be controlled: this means that the effect of the EVs and CVs on the DV can be minimised. Cause-and-effect between the IV and DV can be demonstrated (high internal validity).
-Can be more easily replicated: greater control means less chance that new EVs are introduced. This means that findings can be confirmed, supporting their validity
Lab Experiment: Negatives + Explanations
-May lack generalisability: the controlled lab environment may be artificial and participants are aware they’re being studied. Behaviour may not be natural and can’t be generalised to every day life, which means there is no external validity.
-Demand characteristics: cues in the experimental situation that invite a particular response from participants. The findings may be explained by these keys, rather than the effect of the IV (lower internal validity).
Types of experiment: Field Experiment
A natural setting. The IV is manipulated and the effect on the DV is recorded
Field Experiment: Positives + Explanations
-More natural environment: participants are more comfortable and behaviour is more authentic. results may be generalisable to everyday life
-Participants are unaware of being studied: they’re more likely to behave as they normally do so the findings can be generalised. it’s more difficult to establish cause and effect than in a lab.
-There are ethical issues: participants in a field experiment may not have given informed consent. this is an invasion of participants’ privacy
Types of Experiment: Natural Experiment
The experimenter doesn’t manipulate the IV - it does change but the change isn’t made by the experimenter (something else cause the IV to change). DV may be naturally occurring or may be devised by the experimenter and measured in the field or lab.
Natural Experiment: Positives + Explanations
-May be the only practical/ethical option: it may be unethical to manipulate the IV. A natural experiment may be the only way causal research can be done for topics
-Greater external validity: natural experiments involve real-world issues. this means that findings are more relevant to real experiences
Natural Experiment: Negatives + Explanations
-The natural event may only occur rarely: natural events occur rarely which reduces the opportunity for research. this may limit the scope for generalising findings.
-Participants not randomly allocated: experimenter has no control over which participants are placed in which condition (IV is pre-existing). this means the CV may not be controlled
Types of Experiment: Quasi-Experiment
IV is based on a pre-existing difference between people (e.g. age or gender). No one has manipulated this variable, it just exists. The DV may be naturally occurring or may be devised by the experimenter + measured in field/lab
Quasi-Experiment: Positives + Negatives
-Often High Control: often carried out under controlled conditions (like lab). this means replication is possible
-Comparisons can be made between people: IV is a difference between people in this experiment. this means that comparisons between different types of people can be made.
Quasi-Experiment: Negatives + Explanations
-Participants aren’t randomly allocated: experimenter has no control over which participants are placed in which condition (IV is pre-existing). Participant Variables may have caused the change in the DV acting as a CV
-Causal relationships not demonstrated: researcher doesn’t manipulate/control the IV (like natural ex.). this means we can’t say for certain that any change in the DV was due to the IV.
Sampling: Population
The large group of people that a researcher is interested in studying
Sampling: Sample
A smaller group selected from the target population
Sampling: Bias
Most samples are biased in that certain groups may be over or under represented
Random sampling
Equal chance. Every person in the target population has an equal chance of being selected.
How is random sampling carried out
Lottery method
Positive of random sampling
EVs/CVS are controlled which enhances internal validity
Negative of random sampling
Time consuming and may not work. A complete list of the target population is hard to get and some participants may refuse to participate
Systematic sampling
Using a set system. Participants are chosen using a set pattern (sampling frame)
How is systematic sampling carried out?
Every nth person is selected from a list of the target population
A positive of systematic sampling
It is unbiased. The first item is usually selected at random as there’s an objective method
A negative about systematic sampling
Takes time and effort. A complete list of the target population is required so you may as well use random sampling
Stratified sample
Strata. Sample reflects proportions of people is certain subgroups (strata) within a population.
How is stratified sample carried out?
Subgroups (strata’s) are identified. The relative percentages of the subgroups in the population are reflected in the sample.
A positive of stratified sample
It’s a representative method. The characteristics of the target population are represented. Generalisability is more likely than other methods.
A negative of stratified sample
Stratification isn’t perfect because strata can’t reflect all the ways in which people are different meaning complete representation isn’t possible.
Opportunity sample
Most available. People who are simply most available
How is opportunity sample carried out?
Asking people nearby
A positive of opportunity sample
Quick method. Opportunity sampling is convenient because you just make use of the people who are closest. Makes it cheaper and one of the most popular sampling method
A negative of opportunity sampling
Inevitably biased. The sample is unrepresentative of the target population as it’s drawn from a very specific area. This means that findings can’t be generalised
Volunteer sample
Self selecting. Participants select themselves
How is volunteer sample carried out
Advertising
A positive of volunteer sampling
Participants are willing. Participants have selected themselves and know how much time and effort is involved.p meaning they’re likely to engage more than people stopped in the street
Negative of volunteer sampling
Volunteer bias. Participants may share certain traits meaning findings can’t be generalised
Ethical issues
- When a conflict exists between the rights of participants and aims of the research.
-BPS codes of conduct is a quasi-legal document to protect participants based on four principles: respect, competence, responsibility, and integrity. - ethics, committees way up costs (for example potential harm) and benefits (for example, value of research) before deciding whether a study should go ahead.
Informed consent
Informed consent involves making participants aware of the aims of the research, the procedures, their rights (including the right to withdraw partway through the investigation should they so wish), and also what their data will be used for.
Participants should then make an informed judgement whether or not to take part without being coerced or feeling obliged.
May reveal aims
Ways of dealing with informed consent
Signed consent form, where appropriate seek parental consent
What are the three alternative ways of getting informed consent?
- Presumptive: ask a similar group if the study is acceptable
- Prior general: agree to be deceived -> achieved by participants agree to take part in many different studies
- Retrospective: get consent after the study
Deception
deliberately misleading or withholding information from participants at any stage of the investigation so consent isn’t informed
Despite that, there are occasions when deception can be justified if it does not cause the participant undue distress.
How to resolve deception
-At the end of a study, participants should be given a full debrief.
-participants should be made aware of the true aims of the investigation and any details they were not supplied with during the study, such as the existence of other groups or experimental conditions.
-Participants should also be told what their data will be used for and must be given the right to withhold data if they wish.
-This is particularly important if retrospective consent is a feature of the study (see right).
Protection from harm
- As a result of their involvement, participants should not be placed at any more risk than they would be in their daily lives, and should be protected from physical and psychological harm.
- The latter includes being made to feel embarrassed, inadequate or being placed under undue stress or pressure.
How to resolve protection from harm
- participants should be given the right to withdraw at each stage of the research process
- should be reassure that their behaviour was normal/typical during the debriefing
- researcher should provide counselling if participants have been distressed
Privacy and confidentiality
- Participants have the right to control information about themselves.
- This is the right of privacy. If this is invaded then confidentiality should be protected.
- Confidentiality refers to our right, enshrined in law under the Data Protection Act, to have any personal data protected.
- The right to privacy extends to the area where the study took place such that institutions or geographical locations are not named.
