Psy 2003 Review Sheet One

 I.                   Data Techniques

a.      Frequency distributions           

                                                               i.      Stem-and-leaf plots

                                                             ii.      Box plots

b.      Measures of central tendencies

                                                               i.      Mean

                                                             ii.      Median

                                                            iii.      Mode

                                                           iv.      When should we use the median or mode?

                   c.  Measures of variability

                                i. variance

                                ii. standard deviation

                                iii. Interquartile range

                                iv. range

II.                Probability Concepts

a.      Basic definition

b.      Probability of A and B

c.      Probability of A OR B

d.      Probability of A given B (conditional)

e.      Independence: P( A and B)= P(A)P(B)

III.             Applications of Probability

a.      Psychological or Medical tests

                                                               i.      Sensitivity: P(Positive test | disease)

                                                             ii.      Specificity: P(Negative test | No disease)

                                                            iii.      Rate of false positives: P(Positive test | No disease)

                                                           iv.      Rate of false negatives: P(Negative test | Disease)

b.      Application to psychological and medical research

                                                               i.      Risk= P(Disease | Condition)

                                                             ii.      Relative Risk= P(Disease | Condition) / P(Disease | Baseline)

IV.              Binomial Distribution (dichotomous outcome variable and independent trials)

a.      Probability of exactly a: P(x=a)

b.      Probability of at least: P(x >  a)

c.      Probability of at most: P(x <  a)

V.                 Normal Distribution

a.      Standard normal

                                                               i.      Find p given z

                                                             ii.      Find z give p

b.      Non standard normal

                                                               i.      Find p given z = (x-mean)/(standard deviation)

                                                             ii.      Find z given p, then find x= z (standard deviation) + mean

VI.              General Issues

1. Population
2. Random Samples
3. Sample space (the set of all possible outcomes in a probability experiment)
4. Parameter versus Statistic
5. Randomization
6. Measurement scales
7. Sampling error & non sampling error
8. Experimental design (experiments and observational studies)
9. Confounding effects and extraneous variables
10. Qualitative and quantitative variables (discrete, and continuous)
11. Sampling techniques (convenience sampling, simple random samples, stratified random samples and cluster samples)