Experimental Procedure

 Hypothesis – a statement of the results that the experimenter expects – not what he/she already knows – must be made prior to testing

Insomnia vs. Sleeping Pills  Hypothesis – If X number of sleeping pills helps the otherwise healthy person with insomnia then they will sleep better

 Independent variables – the factor that the experimenter manipulates or changes in a study  Dependent Variables – the factor in a study that changes or varies as a result of changes in the independent variables – the results

I. vs. S.P.  IV –one group – sleeping pills –two group – placebo  DV –results can vary – better, worse, or same amount of sleep

 Subjects – people or animals on whom the experiment is conducted –Assigned randomly to groups

 Sample – a group that represents a larger population

I. vs. S.P.  Subjects – two groups similar in physical health, age and sleep patterns

 Experimental Group – the group on which the critical part of the experiment is performed  Control Group – the group that doesn’t participate in the critical part of the experiment

 Control – removal of factors that may get results or alter effects of “medicine”

I. vs. S.P.  Control Group – get placebo  Experimental Group – get sleeping pills

 Placebo – “fake medicine” – has no active ingredients and works by the power of suggestion Pirin Tablets

I. vs. S.P.  Results –hypothesis rejected –Subjects won’t sleep better –Have insomnia worse – less restful  Interferes with dreams because without dreams sleep loses “curative effect”

14 Measures of Central Tendency Mode: The most frequently occurring score in a distribution. Mean: The arithmetic average of scores in a distribution obtained by adding the scores and then dividing by the number of scores that were added together. Median: The middle score in a rank-ordered distribution.

15 Measures of Central Tendency A Skewed Distribution

16 Measures of Variation Range: The difference between the highest and lowest scores in a distribution. Standard Deviation: A computed measure of how much scores vary around the mean.

17 FAQ Q1. Can laboratory experiments illuminate everyday life? Ans: Artificial laboratory conditions are created to study behavior in simplistic terms. The goal is to find underlying principles that govern behavior.

18 FAQ Q2. Does behavior depend on one’s culture? Ans: Even when specific attitudes and behaviors vary across cultures, as they often do, the underlying processes are much the same. Ami Vitale/ Getty Images

19 FAQ Q3. Does behavior vary with gender? Ans: Yes. Biology determines our sex, and culture further bends the genders. However, in many ways woman and man are similarly human.

20 FAQ Q4. Why do psychologists study animals? Ans: Studying animals gives us the understanding of many behaviors that may have common biology across animals and humans. D. Shapiro, © Wildlife Conservation Society

21 FAQ Q5. Is it ethical to experiment on animals? Ans: Yes. To gain insights to devastating and fatal diseases. All researchers who deal with animal research are required to follow ethical guidelines in caring for these animals.