"The design of experiments (DOE or DOX), also known as experiment design or experimental design, is the design of any task that aims to describe and explain the variation of information under conditions that are hypothesized to reflect the variation."
The various types of experimental designs such as within-subjects, between-subjects, and mixed designs.
Hypothesis formulation: The process of coming up with a clear and testable statement about the relationship between two or more variables in an experiment.
Independent and dependent variables: The independent variable is the factor that the researcher manipulates, while the dependent variable is the factor that is measured in response to the manipulation.
Experimental groups: These are the groups of participants that receive different treatments or interventions in an experiment.
Control groups: The group of participants that does not receive any treatment or intervention, used as a point of comparison to the experimental group.
Random assignment: The process of randomly assigning participants to either experimental or control groups to avoid potential bias.
Sampling methods: The process of selecting participants from a larger population to participate in an experiment.
Between-subjects designs: A design where different participants are assigned to different groups and are exposed to different conditions in order to compare their responses.
Within-subjects designs: A design where the same group of participants are exposed to different conditions and their responses are compared.
Factorial designs: A design that involves manipulating more than one independent variable in an experiment.
Counterbalancing: A method used to balance out the effects of order in which different conditions are presented to participants.
Placebo effect: The phenomenon where participants in the control group experience a positive effect simply because they believe they are receiving treatment.
Double-blind designs: A design where both the participants and the researchers are unaware of which participants are assigned to the experimental or control group.
Quasi-experimental designs: A design that lacks a true control group but involves comparing groups that are not randomly assigned.
Correlational studies: A research design that examines the relationship between two variables without any manipulation of variables.
Descriptive studies: A design where researchers simply observe and record behavior without any manipulation of variables.
Pre-Test Post-Test Design: In this design, participants are tested before and after being exposed to the experimental manipulation to assess the effect.
Between-Subjects Design: Participants are randomly assigned to different groups, and each group receives a different treatment.
Within-Subjects Design: Participants receive all treatments or conditions in a randomized order.
Factorial Design: This design combines different variables to test how they interact with each other.
Counterbalanced Design: Participants receive different treatments in different orders to control for order effects.
Quasi-Experimental Design: This design has some similarities to experimental research but lacks random assignment of participants to groups.
Solomon Four-Group Design: This design includes two experimental groups and two control groups, with one experimental group and one control group being pre-tested.
Time-Series Design: The outcome variable is measured repeatedly over time to assess changes due to the experimental manipulation and other factors.
Matched-Pairs Design: Participants are matched according to specific variables and then randomly assigned to different groups.
Double-Blind Design: Both the participants and the researchers do not know who is receiving the experimental treatment.
Single-Blind Design: Participants are not aware of whether they are receiving the experimental treatment or a placebo while researchers are.
Randomized Block Design: Similar to matched-pairs design, participants are divided into blocks, and each block is randomly assigned to different treatments.
"The change in one or more independent variables is generally hypothesized to result in a change in one or more dependent variables, also referred to as 'output variables' or 'response variables.'"
"The experimental design may also identify control variables that must be held constant to prevent external factors from affecting the results."
"Experimental design involves not only the selection of suitable independent, dependent, and control variables but planning the delivery of the experiment under statistically optimal conditions given the constraints of available resources."
"There are multiple approaches for determining the set of design points (unique combinations of the settings of the independent variables) to be used in the experiment."
"Main concerns in experimental design include the establishment of validity, reliability, and replicability."
"For example, these concerns can be partially addressed by carefully choosing the independent variable, reducing the risk of measurement error, and ensuring that the documentation of the method is sufficiently detailed."
"Related concerns include achieving appropriate levels of statistical power and sensitivity."
"Correctly designed experiments advance knowledge in the natural and social sciences and engineering, with design of experiments methodology recognized as a key tool in the successful implementation of a Quality by Design (QbD) framework."
"Other applications include marketing and policy making."
"The study of the design of experiments is an important topic in metascience."