Key science skills Flashcards
Types of investigation methodologies
- controlled experiments
- case studies
- correlational study
- fieldwork
- literature review
- modelling
- simulation
Advantages and disadvantages of controlled experiments
Advantage: allows researchers to infer the relationships between specific variables and draw conclusions about them
Disadvantage: can be time-consuming and expensive to manipulate and measure certain variables
Advantages and disadvantages of case studies
Advantage: provide highly detailed and rich information
Disadvantages: results cannot be generalised to a wide population as they often involve a small group of people or one person
Correlational study v.s. controlled experiment
In a correlational study, researchers observe and measure the relationship between two or more variables without any active control or manipulation of them.
In a controlled experiment, the relationship between two variables is tested in a controlled environment; effect of the independent variable on the dependent variable is tested while aiming to control all other variables
Experimental research designs
- within subjects
- between subjects
- mixed design
Within-subjects design
an experimental design in which participants complete every experimental condition
Between-subjects design
An experimental design in which individuals are divided into different groups and complete only one experimental condition
Mixed design
An experimental design which combines elements of within-subjects and between-subjects designs
Advantages and disadvantages of within-subjects design
Advantage: less people are needed because each participant completes each experimental condition
Disadvantage: completing one experimental condition first may influence how participants perform in the other condition (e.g. due to fatigue, practice)
Advantages and disadvantages of between-subjects design
Advantage: may be less time-consuming as different participants can complete different conditions simultaneously
Disadvantage: Differences between participants across groups can affect results
Advantages and disadvantages of mixed design
Advantage: Allows experimenters to compare results across experimental conditions
Disadvantage: can be more costly and time-consuming
Sampling techniques
- random sampling
- stratified sampling
Random sampling
any sampling technique that uses a procedure to ensure every member of the population has the same chance of being selected
Advantages and disadvantages of random sampling
advantage: it can make a fairly representative sample if the sample is large
disadvantage: time-consuming to ensure every member of the population has an equal chance of being selected
Stratified sampling
any sampling technique that involves selecting people from the population in a way that ensures its strata (subgroups) are proportionally represented in the sample
Process:
1. Dividing the research population into different strata based on characteristics relevant to the study
2. Selecting participants from each stratum to how they appear in the population (randomly or systematically)
Advantages and disadvantages of stratified sampling
advantage: most likely to produce a representative sample
disadvantage: time-consuming and expensive
Extraneous variable
any variable that is not the independent variable but may cause an unwanted effect on the dependent variable
Confounding variable
a variable that has directly and systematically affected the dependent variable, apart from the independent variable
Preventing extraneous and confounding variables
- sampling size and procedures
- experimental design choice
Primary data v.s secondary data
primary data is data collected first-hand by a researcher
secondary data is data sourced from others’ prior research
Quantitative data v.s Qualitative data
Quantitative data is data that is expressed numerically
Qualitative data is data that is expressed non-numerically
Objective data v.s. Subjective data
Objective data is factual data that is observed and measured independently of personal opinion
Subjective data is data that is informed by personal opinion, perception or interpretation
Positions of IV and DV on a bar chart
independent variable = x-axis
dependent variable = y-axis
Accuracy and Precision
Accuracy: how close a measurement is to the true value of the quantity being measured
Precision: how closely a set of measurement values agree with each other
Systematic errors
errors in data that differ from the true value by a consistent amount
causes:
- environmental factors
- observational/researcher error
Random errors
errors in data that are unsystematic and occur due to chance
Causes:
- poorly controlled measurement procedures
- faulty measurement tools
- differences between participants and environment
Repeatability
the extent to which successive measurements or studies produce the same results when carried out under identical conditions within a short period of time
e.g. same procedure, observer instructions and setting
Reproducibility
The extent to which successive measurements or studies produce the same results when repeated under different conditions
e.g. different participants, time, observer and environmental conditions
Internal validity
the extent to which an investigation truly measures or investigates what it claims to
- did experimental design minimise extraneous variables
- was sample and allocation representative and unbiased
- did the IV truly affect the DV
External validity
the extent to which the results of an investigation can be applied to similar individuals in different settings
improving external validity:
- using sampling procedures that create a more representative sample
- diverse and large sample size
Ethical concepts
- beneficence
- integrity
- justice
- non-maleficence
- respect
Beneficence
the commitment to maximising benefits and minimising the risks and harms involved
Integrity
the commitment to searching for knowledge and understanding and the honest reporting of all sources of information and results
Justice
- ensures that there is fair consideration of competing claims
- there is no unfair burden on a particular group involved in the research
- there is fair access to research
Ethical guidelines
- voluntary participation
- informed consent procedures
- confidentiality
- use of deception
- withdrawal rights
- debriefing
Non-maleficence
the principle of avoiding causing harm
Respect
- every living thing has value
- consider culture, beliefs, autonomy, welfare
Voluntary participation
there is no pressure put on the participant to partake in an experiment, they freely choose to be involved
Informed consent procedures
Processes that ensure participants understand the nature and purpose of the experiment, including potential risks, before agreeing to participate
Confidentiality
The privacy, protection and security of a participant’s personal information
Use of deception
Intentionally misleading participants about the true nature of a study.
Can only be used if participants’ knowledge of the true purpose of the experiment would affect the results
Withdrawal rights
the right of participants to be able to discontinue their involvement in an experiment at any time without penalty
Debriefing
a procedure that ensures that participants leave the experiment understanding the aim, results and conclusions
