Exam 2

Exam 2 - Chapter 6 Conducting a Good Experiment I:...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Chapter 6 Conducting a Good Experiment I: Variables and Control The Nature of Variables o Variables o A v ariable is an event or behavior that can assume at least two values. Another word for value is levels/groups/conditions o Operational definition Bridgman (1927) suggested that researchers should define their variables in terms of the operations needed to produce them. Such definitions allow others to replicate your research Independent Variables o Independent variables (IVs) variables that the experimenter purposely manipulates. o Physiological IV Conditions that alters or change the biological state of the participant Examples: Drugs, temperature, sleep deprivation, etc. o Experience Manipulation of the amount or type of training or learning Examples: reinforcement vs punishment/ o Stimulus or environmental IV An aspect of the environment that the experimenter manipulates Participant Characteristics o Participant characteristics : o Aspect of the participant, such as age, sex or personality traits, that are treated as if they are IVs. o They are not True IVs because they cannot be manipulated by the experimenter (They are a classification) Dependent Variables changes as a function of the level of the IV experienced by the participant. A good DV is valid (it measures what the experimental hypothesis says it should measure) and reliable (producing consistent measurements) o Types of Dependent Variables (DV) o Correctness Correct vs. incorrect (look at number of correctly remembered words) o Rate or frequency Rate of responding: how quickly does Ss respond in a certain time period. (in a 5 min period the rat hit the bar 60 times per min) Frequency : the number of responses or events that occur within a specific time period (number of times children interact during free play) o Degree or amount Single number (level of life satisfaction; self esteem score) o Latency or duration Latency : how quickly did the Ss make response (.15 sec to respond to image on screen) Duration : how long did their response last? (Held key down for 30 sec) Nuisance Variables o Nuisance variables o Unwanted variables that can cause the variability of scores within groups to increase o Nuisance variables increase the spread of scores within a distribution; they do not cause a distribution to change its location. o Unwanted variables that can cause the variability of scores within groups to increase (they do not cause a distribution to change its location) o Examples (indicate the nuisance variable and its effect) o An experimenter measures reaction time in participants ranging from 12- 78 o The ability of participants to recall a list of words is being studied in a room with a noisy elevator o The lab where the participants are tested for manual dexterity has frequent, unpredictable changes in temperature Extraneous Variables (Confounders) o Difference between groups can cause the distributions to be closer together or...
View Full Document

Page1 / 13

Exam 2 - Chapter 6 Conducting a Good Experiment I:...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online