VCE Psychology - Key Science Skills

Experiment

A research method used to test a hypothesis under controlled conditions in order to measure the effects of an IV(s) on a DV(s).

Descriptive statistics

Are used to summarise, organize and describe important features of data, so they can be easily interpreted and communicated.

Random sampling

Allocates subjects from the population of interest to form part of the sample such that each member of the population has an equal chance of being selected. If the sample is of sufficient size, it is usually representative of the population.

Stratified sampling

Attempts to prevent biases by making the sample more representative of the population. It involves identifying some of the relevant factors (strata) present in the population such as age, sex, religion, ethnic background, residential area, IQ scores or income level, and then selecting a separate sample from each stratum in the same proportions as the population.

Random allocation

Participants in an experiment are as likely to be in one group as the other (experimental or control group). The purpose is to obtain equivalent groups before introducing the IV and to make sure that any difference in the two groups is due to the IV, not individual characteristics.

Control group

The group of participants that are exposed to the control condition, that is they are not exposed to the independent variable.

Experimental group

The group of participants that are exposed to the experimental condition, that is exposed to the independent variable.

Participants

The people used in an experiment or any other kind of research study.

Sampling

The process of selecting participants for research.

Sample

A group that is a subset or portion of a larger group chosen to be studied for research purposes.

Population

Used in psychological research to describe the larger group from which the sample is drawn.

Biased sample

The sample is referred to as this if not everyone in a target population (population of research interest) has an equal chance of being selected as a participant.

Placebo effect

Refers to an improvement in health or wellbeing due to an individual's belied that the treatment given to them will be effective.

Single-blind procedure

Participants are not aware of the condition of the experiment to which they have been allocated (either the experimental or the control condition).

Experimenter effect

Occurs when there is a change in a participant's response due to the experimenter's actions, rather than to the effect of the IV.

Self-fulfilling prophecy

Is the tendency of participants to behave in accordance with how they believe the experimenter wants them to behave.

Experimenter bias

Is the unintentional bias in the collection & treatment of data by the experimenter.

Double-blind procedure

Neither the participants nor the person collecting data is aware of which group the participants belong to.

Variable

Any factor that can vary (change) in amount or kind over time. I.e. Sexual desire, alcoholic content, happiness, sociability, amount of sleep & degree of masculinity or feminity, sex, blood type, genetic make-up.

Independent variable

The variable, which is systematically manipulated, changed or varied in some way by the experimenter (in order to assess its effect on the participants response).

Dependent variable

Shows any effect of the IV; that is, the aspect of a participant's behaviour or experience that is observed or measured & is expected to change as a result of the manipulation of the IV.

Extraneous variable

Any variable other than the IV that may cause a change in the DV and therefore affect the results.

Confounding variable

Any variable other than the IV that has not been controlled, thereby having an unwanted effect on the DV, & making it impossible to determine which of the variables has produced changes in the DV.

Repeated measures design

Each participant is involved in both the experimental & control conditions of an experiment, so that the effects of individual differences between participant's characteristics balance out exactly.

Order effect

Performance on a problem-solving task that is completed second may be better because of the experience gainined in completing the first task.

Counterbalancing

Involves arranging the order in which the conditions of a repeated measures design are experienced so that each condition occurs equally often in each position.

Matched participants design

Involves selection of pairs of participants who are very similar in a characteristic(s) than can influence the DV, then allocating each member of the pair to different groups.

Independent groups design

Each participant is randomly allocated to one of two (or more) entirely separate (independent) groups.

Operational definitions

Define an observable event in terms of the procedures (or operations) used to measure that event.

Research Hypothesis

states the causal relationship between the independent and dependent variables to be tested.

Conclusion

Is a decision or judgment about what the results obtained from an investigation mean.

Generalisation

A decision or judgment about how widely the findings of a study can be applied, particularly to other members of the population from that the sample was drawn.

Individual participant differences

the differences in personal characteristics and experiences of the individual participants in an experiment.

Placebo

an inactive substance or treatment.

non-standardised instructions and procedures

non-uniform instructions and procedures are given to the participants.

Convenience sampling

involves selecting participants who are readily available without any attempt to make the sample representative of a population.

Standardised instructions

the instructions given to all participants for each condition should be predetermined and identical in terms of what they state and how they are administered ('given').

standardised procedures

the techniques used for making observations and measuring responses should be identical for all individual participants and all participants should be treated in the same way, as appropriate to the experimental condition to which they have been assigned.

qualitative data

information about the 'qualitites' or characteristics of what is being studied. They are descriptions, words, meanings, picutres, texts and so on.

quantitative data

information about 'quantities' or amounts of what is being studied. Usually expressed in the form of units of measurement or numbers, such as raw scores, percentages, means, p values and so on.

case study

an intensive, in-depth investigation of some behaviour or event of interest in an individual, small group or situation.

Observational study

involves collection of data by carefully watching and recording behaviour as it occurs.

observation

any means by which a phenomenon (an observable event) is studied, including the data the represent a phenomenon.

naturalistic observation

a naturally occurring behaviour of interest is viewed by the researcher in an inconspicuous or 'unnoticeable' manner so that their presence does not influence in any way the behaviour being observed.

self-report

is the participants (or responsent's), written or spoken responses to questions, statements or instructions presented by the researcher.

questionnaires

a written set of questions designed to draw out self-report information from people on a topic of research interest.

mean

arthimetical average of all the individual scores (or measures) in a set of scores.

median

the middle socre (or midpoint) of a set of scores.

mode

most frequently occurring score in a set of scores.

measure of central tendency

data is often summarised by determining a single numerical score that can describe the data for the whole group(s). It indicates the 'central' or 'average' value in a set of scores.

ethics

standards that guide individuals to identify good, desirable or acceptable conduct.

confidentiality

any personal details or details of a participants involvement cannot be revealed in a manner that enables individuals to be identified, unless their written consent is obtained.

voluntary participation

the principle that study participants choose to participate of their own free will

withdrawal rights

The experimenter informs the participants that they are free to participate, decline or withdraw from the research at any time without reason should they wish to do so

informed consent procedures

participants must be given information about the nature and purpose of a study before they agree to take part. If they are under 18, a parent/guardian must give consent. Consent is in writing.

deception

method by which participants are misinformed or misled about study's methods and purposes - must be told truth about this in debriefing

debriefing

A step at the end of an experiment in which the researcher explains the study's purpose and design to each participant and undoes any manipulations to participants' beliefs or state.

ethics committee

These people are in charge of approving research in psych, monitoring the ethical standards of an experiment and ensuring psychology is not bought into disrepute.

representative sample

a sample that accurately reflects the characteristics of the population as a whole

aim

The purpose of a study

Operationalised IV

a clearly defined IV

Operationalised DV

clearly defined how the results of a study will be measured.

experiment

A research method in which an investigator manipulates one or more factors to observe the effect on some behavior or mental process under controlled conditions. Tests a hypothesis.

Use of animals in research

Must be directly supervised by a person competent to ensure their comfort, health and humane treatment.

professional conduct

Behaviour and communication that inspires trust and confidence in the participants, follows all ethical guidelines.

Reliability

Ability of a test to yield very similar scores for the same individual over repeated testings

Validity

the extent to which a test measures or predicts what it is supposed to

Replication

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances

Bias

A particular preference or point of view that is personal, rather than scientific.

standard deviation

a computed measure of how much scores vary around the mean score

evidence-based conclusion

making a judgment about what the results in an experiment in relation to theory.

implications

the conclusion that can be drawn from something although it is not explicitly stated. i.e. what to do the results of the experiment mean for those in the future?

cross-sectional study

A study in which a representative cross section of the population is tested or surveyed at one specific time.

objective data

information that is seen, heard, felt, or smelled by an observer; signs

subjective data

things a person tells you about that you cannot observe through your senses; symptoms

primary data

information that is collected for the first time; used for solving the particular problem under investigation

secondary data

information that already exists somewhere, having been collected for another purpose

interviews

A form of self-report which involves formal or informal approach to elicit information from stakeholders by talking to them directly.