key science skills Flashcards
The scientific
method
The scientific method is a procedure used to obtain knowledge that involves hypothesis formulation, testing, and re-testing through processes of experimentation, observation, measurement, and recording.
theory
a theory is a proposition or set of principles that is used to explain something or make predictions about cause and effect.
modeles
a model is a representation of a concept, process, or behaviour often made to simplify or make something easier to understand
Aims
in psychological research, an aim is a statement outlining the purpose of the investigation.
the aim of this study is to investigate the
Hypothesis
a hypothesis is a testable prediction about the outcome of an investigation.
what should a hypothesis include
I. P. A. D
the independent variable and the dependent variable.
the population,
‘direction’ of results; for example, that some outcome was ‘more likely’ or ‘less likely’,
independent Variables (IV)
I manipulat
independent variable (IV) is the variable for which quantities are manipulated (controlled, selected, or changed)
dependent variable (DV)
the dependent variable (DV) is the variable the researcher measures in an experiment for changes it may experience due to the effect of the independent variable.
Controlled variables
controlled variables are variables other than the IV that a researcher holds constant (controls) in an investigation, to ensure that changes in the DV are solely due to changes in the IV.
what is the point of Controlled Experiments – Research Designs
strictly manipulate variables of interest (independent variables) in a controlled environment and measure their effect on another variable (the dependent variable).
infer a more causal relationship between variables.
how does a In controlled experiment work
an experimental group refers to the group of participants in an experiment who are exposed to a manipulated independent variable (i.e. a specific intervention or treatment).
- A control group refers to 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
A within-subjects design is an experimental design in which participants complete every experimental condition.
Between Subjects Design
A between-subjects design is an experimental design in which individuals are divided into different groups and complete only one experimental condition.
Mixed Design
Combines elements of within-subjects and between-subjects designs.
This allows experimenters to note differences that occur within each experimental group over time, and also compare differences across experimental groups.
case studies
A case study is an in-depth investigation of an individual, group, or particular phenomenon that contains a real or hypothetical situation
Correlational studies
A correlational study is a type of non-experimental study in which researchers observe and measure the relationship between two or more variables without any manipulation of them. The variables under investigation are only measured and not manipulated, unlike in experiments.
Correlational research aims to find relationships between variables, describe them, and make predictions on the basis of them.
Population
The population of an experiment refers to the group of people who are the focus of the research and from which the sample is drawn. For example, year 12 VCE Psychology students
sample
from the population, a sample is drawn, they are a subset of the population who participate in a study. The sample could be 10 Psychology classes across the state
A sample’s results can then be used to make conclusions about the wider research population; this is referred to as generalising results.
Sampling Techniques
1. Convenience Sampling
refers to any sampling technique that involves selecting readily available members of the population, rather than using a random or systematic approach.
- Random Sampling
Refers to any sampling technique that uses a procedure to ensure every member of the population has the same chance of being selected.
- Stratified Sampling
Within any given population, there are different subsets of people called strata. Strata reflect different demographic characteristics, such as age, socioeconomic status, or gender. Stratified sampling involves selecting people from the population in a way that ensures that its strata (subgroups) are proportionally represented in the sample.
The process of stratified sampling involves:
- dividing the research population into different strata based on characteristics relevant to the study.
- selecting participants from each stratum in proportion to how they appear in the
population. This selection
Allocation
Allocation refers to the process of assigning participants to experimental conditions or groups.
For example, in a study testing the effect of a new drug, there may be a control group (receives no active treatment) and an experimental group (receives the trial drug).
Half of the sample will need to be allocated to each group:
Random allocation: ensures every sample participant has an equal chance of being allocated to any group within the experiment
A study is either using random or non-random allocation
Extraneous Variables
is any variable that is not the independent variable but may cause an unwanted effect on the dependent variable
these variables should be controlled (kept constant between experimental groups), or at least monitored, so that they do not interfere with the results.
Confounding Variables
efers to a variable that has directly and systematically affected the DV, apart from the IV
may have been an extraneous variable that has not been controlled for, or a variable that simply cannot be controlled for
interfere with the investigation by providing alternate explanations for the results, it cannot be confirmed whether the IV or confounding variable caused the changes to the DV
can only be identified at the end of a study