Science Inquiry Skills Flashcards
Hypothesis
- The population (group of research interest)
- All conditions of the independent variable
- The dependent variable
0 A prediction
Experimental Design
Controlled trials where investigator manipulates the independent variable to examine the behaviour (dependent variable).
In experimental groups, participants are exposed to the experimental condition (the IV).
In a control group, participants are not exposed to the IV.
Used to suggest causality (ie IV causes DV to occur)
Advantages
- Extraneous variables can be minimised (more control over extraneous variables than other designs)
Because of strict conditions and control, the experimenter can replicate the experiment to check results (reliability)
Disadvantages
- Experimental situation may not relate to real world or naturally occurring behaviour (low ecological validity)
Observational
The investigator collects data but in natural setting by means of behavioural observations or self-report methods.
The groups in these studies are divided based on pre-existing differences (ie. age) rather than manipulating IV.
Therefore, the researcher is not manipulating the IV.
Relationships or correlation can be established.
Advantages
- Higher ecological validity (real life)
- Allows investigation of things that would be unethical, impossible or too expensive under experimental design
- Some kinds of behaviour can only be observed in a naturalistic setting.
Disadvantages
- Only correlation established (Can’t infer a cause and effect or causation)
- Greater chance of extraneous variables due to low control
Cannot replicate findings as the same setting won’t occur naturally again - Doesn’t allow generalisation of findings to the general population
Qualitative
If research is about meanings, experiences, or something complex as investigator wants to allow participants to explain their views/ideas then a qualitative design may be used.
The data is collected by open ended questions and may be verbal interactions, interviews or via focus groups or Delphi technique.
Data is used to examine trends and themes
Advantages
- Rich verbal data
- Further ideas can be developed and explored
- Good for illiterate people
- More convenient than one on one interview
- Can be inexpensive
Disadvantages
- No causation
- People may not feel comfortable expressing opinions
- A few people can dominate the discussion
- Interview bias
Ethics
- Coercion (voluntary participation)
- Anonymity (Confidentiality)
- Right to Withdraw
- Deception
- Unsure Stress or Harm
- Debrief
- Informed consent
Population and Sample
Population: The group researchers want to know about
Sample: The sample of the population who participates in the research
How does sample impact data?
Size: If too small, then extraneous variables can affect results.
Representative: If the sample is not a true representation of the population, it may affect the results.
Random v Stratified
Random: From random selection, could be anyone.
Stratified: Breaks the population down into smaller groups and random samples are taken from the smaller groups in the same proportion as they are in the population.
Constant v extranous variables
Constant: Are controlled during the different conditions of the investigation.
Extraneous: Are any variable that is not being measured and can potentially effect results.
- Participant variables (Age)
- Situational variables (Time of day)
- Experimenter (Bias to certain participants)
variables - Demand characteristics
(Social desirability, expectancy effect)
Confounding variable
If extraneous variable in an experiment, apart from the IV, whose unwanted effect on the DV might be confused with the effect other IV.
If variables are not controlled and they do have an effect on the DV, they become confounding variables.
This means that an EV, not the IV might have a change in the results.
Therefore the
researchers could not be confident in the causation.
Operationalising the hypothesis
- Refers to how you will define and measure the variables.
- It means you need to be clear on how you are manipulating the IV and measuring the DV.
- Be clear on how the quantitative data is being collected (eg. ….number of words on a recall task)
Objective Data
- Directly observed and verified by research.
- Free from bias.
- Does not get comprehensive insight into beliefs emotions etc.
- Heart rate, reaction time, height
Subjective Data
- Self-reports
- Determined by research participants, not accurate.
- A survey on how much sleep you had one week.
Qualitative v Quantitative
Qual:
Advantages – eg deeper understanding of participants, detailed
Limitations – eg more difficult to control, personal bias in interpreting data
Quant:
Advantages – eg strict conditions, restricted focus, easier to summarise and interpret
Limitations – eg restricted focus doesn’t allow participants to explain their responses
Reliability v Validity
Reliability: Measure of consistency of results.
Validity: How well the test measure what it is supposed to accuracy.
- External validity – can the results of the study be generalised to other settings, other people or over time.
- Internal validity – are the effects observed in the study due to the manipulation of the IV or due to another factor.
