The Psychological Experiment
The Psychological Experiment
Objective observation of phenomena that are made to occur in a strictly controlled situation in which one or more factors are varied and others are kept constant
Active intervention by researcher that is expected to produce changes in the dependent variable
An extraneous variable that if not controlled for will eliminate the researcher's ability to claim that the IV causes changes in the DV
Description of the consequences of manipulating an independent variable
Explaining the mechanisms through which a causal relationship operates
An experimental research study that is conducted in a real life setting
An experimental research study that is conducted in the controlled environment of a laboratory
An experimental study that is conducted over the Internet
Non-experimental quantitative research
Type of research in which the independent variable is not manipulated by the researcher
The concept and components of an experiment
Based on the definition(Zimney,1961), there are three rules
Accept the possibility that mistakes can occur
To identify potential mistakes
Take the necessary steps to avoid the errors
Manipulation- observe the phenomena that are made to occur
When conducting an experiment, the psychologist precisely manipulates one or more independent variables and objectively observes the phenomena that are made to occur by this manipulation.
Experimenters identify the cause-and-effect relationships from experimentation by noting the effect or lack of effect produced by their manipulations.
Strictly controlled situation
Only one or more factors are varied
The others are kept constant
Objective Observation- used standardized instruments to measure anxiety
Made the key phenomena occur- administered the two conditions
Varied only IV and held all other variables constant- IV drug vs. placebo, by starting with the random assignment in the two groups the same in every way except administering a different type of pill
The psychological experiment is the best method for identifying causal relationships.
Such instances not only emphasize the importance of causal explanation but also help explain why much scientific research is directed toward explaining how and why something happens.
Ability to Manipulate Variables
Experimental research is the only research method in which the researcher can actively manipulate one or more independent variables and observe the outcome.
Control is achieved by using techniques as random assignment and matching to equate the groups on all variables except for the independent variable, which is purposively varied to create different experimental conditions for comparison.
Cannot apply to nonmanipulated variables
Why-> Some IV cannot be controlled by experimenter, e.g. people’s ages, gender, weather, past events
Solution-> We can investigate these variables and use nonexperimental research designs.
Why-> Artificiality atmosphere is different from real situation
Solution-> The issue is a problem only when an individual makes a generalization from an experimental finding without first determining whether the generalization can be made beyond the laboratory setting.
Inadequate Method of Scientific Research
Why-> Experimental approach is an inappropriate paradigm because it promotes the view that humans are manipulability mechanistic objects.
Solution-> This criticism has been satisfied through the use of qualitative and mixed research methodologies
Experimental Research Settings
Advantage-> excellent for studying many problems
Disadvantage-> control of extraneous variables cannot be accomplished as well as it can be in laboratory experiments
Advantage-> epitomizes the ability to control or eliminate the influence of extraneous variables
Disadvantage bringing the problem into an environment apart from the participants' normal routines
(1) ease of access to demographically and culturally diverse participant populations
(2) bringing the experiment to the participant instead of the opposite;
(3) high statistical power by enabling access to large samples;
(4) the direct assessment of motivational confounding
(5) cost savings
(1) multiple submissions, (2) lack of experimental control, (3) self-selection, (4) dropout.