Experimental 2. Flashcards
Independent variable
What is being manipulated
Dependent Variable
What is being measured.
Controlled Variables
Variables other than the IV that the researcher holds constant so that changes in the DV are due to changes in the IV.
Controlled Experiments
The relationship between 2 variables is tested in a controlled environment; the effect of the IV on the DV is tested while aiming to control all variables.
Investigation methodologies
- Controlled Experiment
- Case Study
- Correlational Studies
Case Study
In-depth investigation of an individual or group that contains a real or hypothetical situation.
Correlational Studies
Observe and measure the relationship between 2 or more variables without any active manipulation.
Variables under investigation are only measured not manipulated unlike experimental.
Classification
Arrangement of phenomena, objects or events into manageable sets.
Identification
Recognition of phenomena as belonging to particular sets.
Fieldwork
Research involving observation and interaction with people and environments in real-world settings conducted outside of the lab.
Literature review
Collating and analysing secondary data related to other people’s scientific findings and/or viewpoints, to answer a question or provide background information.
Modelling
Constructing or manipulating a representative model.
Product, Process or System development
Design/evaluation of an artefact, process or system to meet a human need.
Simulation
Using a model to study the behaviour of a real or theoretical system.
Experimental Group
Exposed to a manipulated IV.
Control Group
Receive no experimental treatment or intervention in order to serve as a baseline for comparison.
Controlled experimental designs
- Within-Subjects
- Between-Subjects
- Mixed
Within-Subjects Design
Complete both experimental and controlled.
+ Fewer people are needed as each participant completes each condition.
- Participants dropping out of the experiment.
Between-Subjects Design
Complete experimental or controlled.
+ May be less time-consuming.
- Larger sample size.
Mixed-Design
Combines elements of both Within and Between. Note differences that occur within each experimental group overtime and compare differences.
+ Multiple experimental groups to be compared to baseline.
- Costly and time-consuming.
Confounding
Directly associated with an experiment that has an effect.
Extraneous
Any variable that is not the independent variable but may cause an unwanted effect on the dependent variable.
Examples of EV and confounding
- Participant-related variables.
- Experimenter effects.
- Situational Variables.
Participant-related variables.
Characteristics of a study’s participants that may affect the results.
Experimenter effects.
Expectations of the researcher affect the results of an experiment (BIAS). More likely to pay attention to what confirms their expectations.
Situational variables
Any environmental factor that may affect the DV.
Preventing EV and Confounding Variables
- Sampling size and procedures
- Experimental design choice
- Counterbalancing
- Single-blind procedures
- Double-blind procedures
- Standardised Instructions and procedures.
- Controlled Variables.
Sampling size and procedures
Larger sample size increases representativeness of the population –> generalisations.
Experimental design choice
Choosing an alternative design to minimise extraneous variables.
Counterbalancing
Reduce order effects that involve ordering experimental conditions in a certain way.
Single-blind procedures
Participants are unaware of the experimental group or condition they have been allocated for.
Double-blind procedures
Both participants and experimenters do not know which conditions or group participants are allocated.
Standardised Instructions and Procedures.
Everyone receives the same instructions and procedures.
Controlled Variables.
Hold variables constant.
Accuracy
How close a measurement is to the true value of the quantity being measured.
True Value
The value/range of values, that would be found if the quantity could be measured perfectly.
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.
Random Errors
Errors that are unsystematic and occur due to chance.
Uncertainty
Lack of exact knowledge relating to something being measured.
Repeatability
The extent to which successive measurements or studies produce the same results in the same conditions.
Reproducibility
The extent to which successive measurements produce the same results in different conditions.
Validity
The extent to which investigations truly support their findings or conclusions.
Internal validity
The extent to which an investigation truly investigates what it claims to.
External Validity
The extent to which results of an investigation can be applied to similar individuals in different settings.
Ethical concepts
- Beneficence.
- Integrity.
- Justice.
- Non-maleficence.
- Respect.
Beneficence
Maximise benefits and minimise the risks.
Integrity
Honest reporting.
Justice
Fair consideration; there is no result that is unfair to one group over another.
Non-maleficence
No harm.
Respect
Every living thing has value and the right to make their own decisions.
Ethical Guidelines
- Confidentiality.
- Informed Consent.
- Deception.
- Debriefing.
- Voluntary Participation.
- Withdrawal Rights.
Confidentiality
Privacy, protection and security of a participant’s personal information.
Informed consent
Participants understand the nature and purpose of the experiment, including potential risks (Before the experiment)
Deception
Intentionally misleading participants on the true nature of the experiment.
Debriefing
At the end of the experiment, participants leave understanding the experiment’s aim, results and conclusion.
Voluntary Participation
No pressure is put on participants to partake in the experiment; there must be free will.
Withdrawal Rights
Right of participants to discontinue involvement in an experiment at any time.
