Key Science Skills

models

a representation of a concept, process, or behaviour, often made to simplify or make something easier to understand

theories

a proposition or set of principles that is used to explain something or make predictions about relationships between concepts

aim

statement outlining the purpose of an investigation

hypothesis

a testable prediction about the outcome of an investigation

5 things to add when writing a hypothesis

Independent variables

Dependent variables

Mention of all groups/conditions being tested

A clear direction for the relationships between variables

Start with “it is hypothesised that…”

independent variables

manipulated and the effect on the DV

dependent variables

being measured and changes are due to effect of IV

controlled variables

held constant to ensure changes in DV are solely due to IV

population

group of people who are the focus of the research

controlled experiment

a type of investigation where the effect of the IV on the DV is testing while aiming to control all other variables

case study

an in-depth investigation of an individual, group, or particular phenomenon that contains a real or hypothetical situation and includes the complexities that would be encountered in the real world

case study advantages

they allow phenomena to be examined in depth which can provide ideas for future studies and hypotheses

case study disadvantage

results can not be applied to a wider population as case studies often only involve a small group or a single individual

correlational studies

a type of non-experimental study in which researchers observe and measure the relationship between two or more variables without any active control or manipulation of them

correlational study advantage

there is no manipulation of variables required

correctional study disadvantage

thier results can not draw conclusion about cause and effect

6 other investigation methodology

classification and identification, fieldwork, literature review, modelling, product, process or system development and simulation

experimental group

group of participants in an experiment who are exposed to a manipulated IV

control group

the group of participants in an experiment who receive no experimental treatment or intervention in order to serve as a baseline for comparison

within-subjects design

an experimental design in which participants complete every experimental condition

an advantage of using a within-subjects design

ensures results are due to independent variables then any differences between participants that would occur if they were in seperate groups

a disadvantage of using a within-subjects design

it can produce order effects

between subjects design

an experimental design in which individuals are divided into different groups and complete only one experimental condition

an advantage of using a between-subjects design

does not create order effect

a disadvantage of using a between-subjects design

differences between participants across groups can affect results

mixed design

an experimental design which combines elements of within-subjects and between-subjects design

an advantage of using a mixed design

allows experimenters to compare results across experimental conditions and across participants

a disadvantage of using a mixed design

can be more costly and time consuming to plan, conduct and analysis

5 types of fieldwork

direct observation, qualitative interviews, questionnaires, focus groups and yarning circles

sample

a subset of the research population who participate in a study

3 types of sampling

convenience sampling, random sampling and stratified sampling

convenience smapling

any sampling technique that involves selecting readily available members of the population

an advantage of convenience sampling

time and cost effective

a disadvantage to convenience sampling

can produce unrepresentative sample

random sampling

any sampling technique that uses a procedure to ensure every member of the population has the same chance of being selected

an advantage of random sampling

reduces experimenter bias in selecting participants

a disadvantage of random sampling

time consuming to ensure every member of a 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 that its subgroups are proportionally represented in the sample

an advantage of stratified sampling

produces most representative data

a disadvantage of stratified sampling

time consuming and expensive

allocation

the process of assigning participants to experimental conditions or groups

extraneous variable

any variable that is not the independent variable but may cause an unwanted effect on the dependent variable

confounding variables

a variable that has directly and systematically affected the dependent variable, apart from the independent variable

6 types of confounding variables

Participant-related variables, order effect, placebo effect, experimenter effect, situational variables, non-standardised instructions and producers and demand characteristics

Participant-related variables

characteristics of participants that may affect results

how to deal with participant-related variables

sampling size and procedures

sampling size and procedures

increasing sample size so its more representative of population

Order effect

the tendency for the order in which participants complete experimental conditions to have an effect on their behaviour

how to deal with order effect

counterbalancing

Placebo effect

when participants respond to an inactive substance or treatment as a result of their expectations or beliefs

how to deal with placebo effect

placebo and single-blind procedures

Experimenter effects

when the expectations of the researcher affect the results of an experiment

how to deal with experimenter effects

double-blind procedures

Situational variables

any environmental factor that may affect the dependent variable

how to deal with situational variables

standardised testing conditions and procedures

Non-standardised instructions and procedures

when directions and procedures differ across participants or experimental conditions

how to deal with

Demand characteristics

cues in an experiment that may signal to a participant the intention of the study and influence their behaviour

counterbalancing

a method to reduce order effects that involves ordering experimental conditions in a certain way

primary data

data collected first-hand by a researcher.

secondary data

data sourced from others’ prior research, not collected directly by the current researcher

quantitative data

data that is expressed numerically

qualitative

data that is expressed non-numerically

objective data

factual data that is observed and measured independently of personal opinion

subjective data

data that is informed by personal opinion, perception, or interpretation

measures of central tendency

mean, medium and mode

mean

average

median

middle value of data

mode

most frequently occurring value in data set

outlier

a value that differs significantly from other values in data set

measures of variability and 2 types of measures

statistics that summarise and describe the spread and distribution of a data set. Range and standard deviation

range

a measure of variability that is a value obtained by subtracting the lowest value in a data set from the highest value

standard deviation

a measure of variability, expressed as a value that describes the spread of data around the mean

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

Systematic errors can be caused by…

Systematic errors affects are…

Systematic errors can be reduced by…

random errors

errors in data that are unsystematic and occur due to chance

Random errors can be caused by…

Random errors affects are…

Random errors can be reduced by

Personal errors

Personal errors can be caused by…

Random errors affects are…

Random errors can be reduced by…

uncertainty in data

the lack of exact knowledge relating to something being measured due to potential sources of variation in knowledge

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

reproducibility

the extent to which successive measurements or studies produce the same results when repeated under different conditions

internal validity

the extent to which an investigation truly measures or investigates what it claims to

Interval validity can be achieved by

external validity

the extent to which the results of an investigation can be applied to similar individuals in different settings

External validity can be improved by…

conclusion

a statement that summarises the findings of a study, including whether the hypothesis was supported or rejected

5 ethical concepts

beneficence, integrity, respect, justice and non-maleficence

beneficence

commitment to maximising benefits and minimising risks and harm

integrity

commitment to honest reporting

justice

obligation to ensure that there is fair consideration of competing claims