Scientific processes

Aim

What the researcher is wanting to investigate and find out.

Hypothesis

A testable prediction, often implied by a theory

Types of hypotheses

directional, non-directional, null and alternative

Non-directional vs Directional hypothesis

Also known as two-tailed and one-tailed. Non-directional predicts an outcome which has no specific turn (direction i.e increase, decrease) while directional predicts an outcome which has a specific turn.

Null hypothesis

Null states that there will be no difference and any difference is due to chance. Used for an insignificant result.

Alternative hypothesis

Alternative states that there will be a difference, stating the researcher's hypothesis to be true. Used for a significant result.

Types of sampling

random, systematic, stratified, opportunity, volunteer.

Population vs Sample

Population is the whole group while a sample are parts of the population.

Random sampling

a sample that fairly represents a population because each member has an equal chance of inclusion. i.e Putting names in a hat and picking out the number of participants through those names. Take names out of hat after selection to avoid repeats.

Systematic sampling

A procedure in which the selected sampling units are spaced regularly throughout the population - every n'th unit is selected.

Stratified sampling

A sample where the population is divided into groups with a common attribute and a random sample is chosen within each group.

Opportunity sample

A sample where participants are chosen because they are easily available.

Volunteer sample

A sample where participants are chosen from a group of people who wish to participate (volunteers).

Pilot studies

Small scale trials of proposed studies.

Aims of piloting

allows the researcher to test the effectiveness, identify any potential issues and to modify the design or procedure, saving time and money in the long run.

Experimental designs

• repeated measures

• independent groups

• matched pairs

Repeated measures

The same/every participant takes part in each condition of the experiment.

Independent groups

Different participants are used in each condition of the experiment - they are randomly allocated to their condition.

Matched pairs

Participants are matched on a key variable and then one of each pair is allocated to a different condition.

Observational design

• behavioural categories

• event sampling

• time sampling

Behavioural categories

When a target behaviour is broken up into components that are observable and measurable (operationalised)

Event sampling

A target behaviour/event is first established then the observer records this event every time it occurs.

Time sampling

The procedure of observing/recording behavior during intervals.

Questionnaire construction

• open and closed questions

• structured and unstructured interviews

Open and closed questions

• open questions have multiple responses as they are flexible. produces qualitative data.

• closed questions have limited responses as they're phrased to provide fixed answers. produces quantitative data.

Structured and unstructured interviews

Structured: a fixed set of questions are provided., more reliability, less validity Unstructured: a prompt is provided but the interviewer is free to be flexible, less reliability, more validity, Semi-structured: A mix of both

Variables

• independent

• dependent

• extraneous

• confounding

Independent variable

Variable that is manipulated

Dependent variable

Variable that is measured

Extraneous variable

A variable other than the IV that can cause unwanted changes to the DV

Confounding variable

A variable other than the IV that has caused unwanted changes to the DV

Controlling extraneous variables

• random allocation

• counterbalancing

• randomisation

• standardisation

Random allocation

Allocating participants to experimental groups or conditions using random techniques - used in independent measures.

Counterbalancing

A method of controlling for order effects in a repeated measure design by either including all orders of treatment or by randomly determining the order for each subject

Randomisation

The use of chance in order to control for the effects of bias when deciding the order of conditions.

Standardisation

Using the exact same procedures and instructions for all participants.

Demand characteristics / Hawthorne effect

When participants behave differently/abnormally because they know they are in an experiment.

Investigator effects / Investigator bias

Anything that the researcher does to effect the participant's performance in a study.

Ethics + the role of the british psychological society's code of ethics

Role of peer review

To ensure research that is published is conducted properly and high quality. Researched is assessed by other experts in the same field.

Implications of psychological research for the economy

Link findings of research to how it can boost the economy (e.g. attachment and parents working) or save money (e.g. treatment of mental illness returns more people to work)

Reliability

How consistent results (of a measure) are across research.

Assessing reliability

• test-retest

• inter-rater/inter-observer

test-retest reliability

using the same test on two different occasions (preferably a long time apart) to measure consistency

inter-rater reliability

measure of agreement among observers on how they record and classify a particular event.

Validity

The extent to which you're actually measuring exactly what you intend to measure

Types of validity

• face validity

• concurrent validity

• temporal validity

• external validity

• internal validity

External validity and types

whether our results can be generalised beyond the study.

• population (target people) validity, ecological (real life) validity, temporal (time) validity

Internal validity

the degree to which the effects observed in an experiment are due to the IV only

Face validity

Measures whether a test looks like it tests what it is supposed to test.

Features of science

• objectivity and empirical method

• replicability and falsifiability

• theory construction and hypothesis testing

• paradigms and paradigm shifts

Objectivity / empirical method

Scientists must minimise all sources of personal bias and gather evidence through direct observation and experience.

Paradigms and paradigm shifts

Scientific subjects have a shared set of assumptions and a scientific revolution occurs when there is a paradigm shift

Reporting psychological investigations/Scientific report:

• abstract

• introduction

• method

• results

• discussion

• referencing

Abstract

Contains a summary of the report

Introduction

Talks about aims, why research was done and maybe researcher's background

Method

Describes the procedure of the research

Discussion

Finds a conclusion by using the results