Presentation on theme: "CONDUCTING EXPERIMENTS The APA (American Psychological Association) sets guidelines for conducting experiments."— Presentation transcript:
CONDUCTING EXPERIMENTS The APA (American Psychological Association) sets guidelines for conducting experiments.
Experiments are the most used research method of psychologists. They answer the question of cause and effect.
Guidelines for Animals Provide comfortable environment (or as much as possible given the experiment) Follow local laws Must do research under a qualified person Benefit to humanity must outweigh any harm to the animal
Reasons to Use Animals Shorter life span Reproduce quicker Environment can be controlled more completely Can do things to animals that you can’t do to humans Some are similar enough to humans that we can apply the research to us
When using animals, we must guard against anthropomorphism – giving animals human characteristics. They don’t respond the same as us so this could bias the experiment.
Guidelines for Humans All information is confidential; privacy of subjects should be protected. Subjects may withdraw at any time. Subjects must be protected from physical and psychological harm. Any harm done must be undone.
Experimenter and subject agree concerning responsibilities. Informed consent must be given after the subject has been told the general nature (overview) of the experiment. Sometimes, deception is required but must be justified.
EXPERIMENTS When conducting experiments, you will need to identify independent and dependent variables. The independent variable is the variable being studied or manipulated. The dependent variable is the result.
The easiest way to determine these is to look at your hypothesis. The independent variable will be in the “if” part of the hypothesis. The dependent variable will be in the “then” part of the hypothesis.
Each variable must have an operational definition. That is, it must be specific and testable.
If the brain is larger, then the IQ will be higher. If a plant receives more sunlight, then it will grow larger. If children are prevented from playing with toys by having fences set up, then they will display anger and frustration.
Once the variables are identified, subjects are selected. A subject is any participant (animal or human) in an experiment. Subjects will then be placed in either a control group or an experimental group.
The experimental group will have the independent variable. The control group will not have it. The two groups should be as much alike as possible and any outside factors should be the same.
Problems Subjects may not act “normally” because they know they are being watched or that they are subjects in an experiment. This is called the “Hawthorne Effect.” People may not be representative of the total population.
The experimenter may be guilty of a self-fulfilling prophecy – overlooking evidence that may conflict with his/her hypothesis or unconsciously setting up the experiment to get the results he/she wants.
To prevent this from happening, a researcher may use a double-blind procedure – the experimenters and the subjects don’t know who is in which group (control or experimental) so they can’t unconsciously give away information.
Volunteer bias may skew the results. There may be a placebo effect – the subject believes he had the independent variable and behaves as if he did An example would be believing you took a new headache remedy which helped end your headache when, in reality, you took a sugar pill.
A solution to this is to use a single-blind procedure where the subjects don’t know which group is the experimental group and which is the control group. Each is given a pill that looks the same. If a double-blind procedure is used, neither would know.
It is difficult to guarantee privacy of subjects when it is expected that you report your findings. The experiment may not be replicable so it won’t hold up scientifically. The researcher may make errors in drawing conclusions or generalizing (must be sure to consider all data collected)
Now read pages 32 and 33 in your textbooks. Then answer the two questions on a separate piece of paper. Homework: Read pp. 55-57 and do the worksheet passed out during the reading.