Research Methods - Key Terms

Experimental Method

→ A deliberate change is made to an independent variable in order to measure its effect on the dependent variable

→ Experiments may be laboratory, field, natural or quasi 

Aim

→ A general statement of what the researcher intends to investigate, the purpose of the study 

Hypothesis

→ A clear, precise, testable statement that states the relationship between the variables to be investigated

Directional Hypothesis

→ Tends to be used when the findings of previous research studies suggest a particular outcome

→ include words such as ‘more’ or ‘less’, ‘higher’ or ‘lower’, ‘faster’ or ‘slower’

→ states the direction of the difference or relationship

Non-Directional Hypothesis

→ Tends to be used when there is no previous research or when findings from earlier studies are contradictory

→ states that there is a difference between conditions or groups of people

→ keywords are difference or affects 

Variables

→ any thing that can vary or change within and investigation

→ variables are generally used in experiments to determine if changes in one thing result in changes to another 

Independent Variable

→ Some aspect of the experimental situation that is manipulated by the researcher - or changes naturally - so the effect on the DV can be measured 

Dependent Variable

→ We measure the effect the Iv has on the DV

Operationalisation

→ clearly defining variables in terms of how they can be measured

Extraneous Variable

→ any variable, other than the independent variable, that may affect the dependent variable if it is not controlled 

Demand Characteristics

→ Any cue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose of an investigation

→ This may lead to a participant changing their behaviour within the research situation

Investigator Effects

→ Any effect of the investigators behaviour (conscious or unconscious) on the research outcome

→ This may include everything from the design of the study to the selection of, and interaction with, participants during the research process

Randomisation

→ The use of chance methods (e.g. tossing a coin or random number generators) to control for the effects of bias when designing materials or deciding the order of experimental conditions 

Standardisation

→ Using exactly the same formalised procedures and instructions for all participants in a research study

Experimental Design

→ The different ways in which participants can be organised in relation to the experimental conditions

Independent Groups Design

→ Participants are allocated to different groups where each group represents one experimental condition

Repeated Measures

→ All participants take part in all conditions of the experiment

Matched Pairs Design

→ Pairs of participants are first matched on some variables that may affect the dependent variable

→ Then one member of the pair is assigned to condition A and the other to condition B

Random Allocation

→ Participants are allocated to conditions in an independent groups design using a random method to control for participant variables 

Counterbalancing

→ An attempt to control for the effects of order in a repeated measures design : half the participants experience the conditions in one order, and the other half in the opposite order

Laboratory Experiment

→ An experiment that takes place in a controlled environment (not necessarily a lab) within which the researcher deliberately changes the IV and records the effect on the DV, whilst maintaining strict control of extraneous variables

Field Experiments

→ An experiments that takes place in a natural setting within which the researcher deliberately changed the IV and the effect on the DV

Natural Experiment 

→ An experiment where the change in the IV is not brought about by the researcher but would have happened even if the researcher had not been there 

→ The researcher records the effects on a DV

→ May take place in a lab or in the field 

Quasi-Experiment

→ A study that is almost an experiment but lacks key ingredients

→ The IV is not determined by anyone - the ‘variables’ simply exist, such as being old or young

→ May take place in a lab or the ‘field’

→ Strictly speaking this is not an experiment

Population

→ The entire group of individuals who are the focus of the researchers interest, from which a smaller sample (the participants) is drawn

Sample

→ A group of individuals who take part in a research investigation

→ The sample is drawn from a population and is presumed to be representative of that population

Sampling techniques

→ The method used to select individuals from the population

Bias

→ In the context of sampling, when certain groups are over or under represented within the selected sample

→ There may be too many younger people or too many people of one ethnic origin in a sample

→ This limits the extent to which generalisations can be make to the population

Generalisation

→ The extent to which findings and conclusions from a particular investigation can be broadly applied to the population

→ This is possible if the sample of participants is representative of the population

Ethical issues

→ These arise when a conflict exists between the rights of participants in research studies and the goals of research to produce authentic, valid and worthwhile data

BPS code of ethics

→ A quasi-legal document produced by the British Psychological Society that instructs psychologists in the UK about what behaviour is and is not acceptable when dealing with participants

→ The code is built around 4 major principles : respect, competence, responsibility and integrity

Pilot study

→ A small scale version of an investigation that takes place before the real investigation is conducted

→ The aim is to check that procedures, materials, measuring scales etc work so that the researcher can make changes or modifications if necessary

Naturalistic observation

→ Watching and recording behaviour in the setting within which it would normally occur

Controlled observation

→ Watching and recording behaviour within a structured environment, i.e. one where some variables are managed

Covert observation

→ Participants’ behaviour is watched and recorded without the knowledge or consent

Overt observation

→ Participants’ behaviour is watched and recorded with their knowledge and consent

Participant observation

→ The researchers become a member of the group whose behaviour they are watching and recording

Non-participant observation

→ The researchers remain outside of the group whose behaviour they are watching and recording

Behavioural categories

→ When a target behaviour is divided into components that are observable and measurable (operationalisation)

Event sampling

→ A target behaviour or event is first established then the researcher records this event every time it occurs 

Time sampling

→ A target individual or group is first established then the researcher records their behaviour at fixed time intervals 

Self-report technique

→ Any method in which a person is asked to state or explain their own feelings, opinions, behaviours and/or experiences related to a given topic 

Questionnaire

→ A set of written questions used to assess a persons thoughts and/or experiences

Interview

→ A ‘live’ encounter when the interviewer asks a set of questions to assess the interviewees thoughts and/or experiences

→  The questions may be pre-set or may develop as the interview goes along 

Open questions

→ Questions for which there is no fixed choice of responses and respondents can answer in any way they wish

Closed questions

→ Questions for which there is a fixed choice of responses determined by the question setter

Correlation

→ A mathematical technique in which a researcher investigates an association between 2 variables

Co-variables

→ The variables investigated within a correlation, for example height and weight

→ They are not referred to as the independent and dependent variables because a correlation investigates the association between 2 variables rather than a cause-and-effect relationship  

Positive correlation

→ As one co-variable changes, the other changes in the same direction

Negative correlation

→ As one co-variable changes, the other changes in the opposite direction

Zero correlation

→ When there is no relationship between the co-variables

Qualitative data 

→ Data that is expressed in words and non-numerical

Quantitative data 

→ Data that can be counted, usually given as numbers 

Primary data

→ Information that has been obtained first-hand by a researcher for the purposes of a research project

Secondary data

→ Information that had already been collected by someone else and so pre-dates the current research project 

Meta-analysis 

→ The process of combining the findings from a number of studies on a particular topic 

→ The aim is to produce an overall statistical conclusion based on a range of studies 

→ Should not be confused with a ‘review’ where a number of studies are compared and discussed 

Descriptive Statistics

→ The use of graphs, tables and summary statistics to identify trends and analyse sets of data

Measures of central tendency

→ The general term for any measure of the average value in a set of data

Mean

→ The arithmetic average calculated by adding up all the values in a set of data and dividing by the number of values 

Median

→ The central value in a set of data when values are arranged from lowest to highest

Mode

→ The most frequently occurring value in a set of data

Measures of dispersion

→ The general term for any measure of the spread of a set of scores

Range

→ A simple calculation of the spread of a set of scores which is worked out by subtracting the lowest score from the highest score 

→ Sometimes 1 is added as a mathematical correction 

Standard deviation

→ A sophisticated measure of spread/dispersion in a set of scores 

→ It tells us by how much, on average, each score deviates from the mean