Mixture of stuff
The pioneer of hypothesis testing
R.A. Fisher
A study that would best rule out chance factors would have a significance level of...
P = .001
(the smaller the P value, the more stringent the level of significance)
P=.05 really means that...
there is only a 5% chance that the difference between the control group and the experimental groups is due to chance factors
Another name for the X axis
abscissa
when subjects know they are part of an experiment/being observed and therefore act differently
Hawthorne effect
the score distance between the 25th percentile and the 75th percentile
interquartile range
In the social sciences the accepted probability level is usually...
.05 or less
Type I and Type II errors are called ____ and ____ respectively
alpha;beta
Another name for the Y axis
ordinate
when a trait which is not being evaluated (attractiveness) influences a researcher's rating on another trait
halo effect
These types of tests always have formal procedures for test administration and scoring
Standardized tests
When sample size increases, Type I and II errors...
decrease
Type I error means...
Type II errors means...
Type I = research rejects the null hypothesis when it is true (false negative)
Type II = researcher accepts the null hypothesis when it is false (false positive)
a negative effect such as when a doctor comments that a person with such and such condition has only six weeks to live
nocebo effect
when an individual begins to fulfill the experimenter's expectations because of the experimenter's beliefs lead them to treat the individual in a special way
Rosenthal effect
a within-person analysis (e.g. was your jog today faster than yesterday?)
ipsatistive
If a researcher changes the significance level from .05 to .001, what happens to alpha and beta errors?
alpha (Type I) errors decrease, beta (Type II) errors increase
The WAIS-IV test is given to 100 adults picked randomly. How many adults would most likely receive an IQ score between 85 and 115?
68%
(On a normal distribution, 68% of people will fall between +/-1 SD)
A sociogram is to a counseling group as a scattergram (scatterplot) is to...
a correlation coefficient
(a scatterplot is a graph of two variables being correlated)
predicts that very high and very low scores will move toward the mean if a test is administered again
statistical regression
(this is a threat to internal validity)
the difference between a sample statistic used to estimate a population parameter and the actual but unknown value of the parameter
Sampling error
In a random sample, each individual in the population has an equal chance of being selected (it is by chance). However, you need to include 20% African Americans in your sample. What type of sampling procedure will be necessary?
Stratified sampling
("stratum" = "special characteristic")
tests a null hypothesis regarding the means of two or more groups after the random samples are adjusted to eliminate average differences
ANCOVA
A platykurtic distribution would look approximately like...
(kurtosis refers to peakedness of a frequency distrubtion)
"plat" sounds like "flat"
If an ANOVA yields a significant F value, you could rely on _____ to test the significant differences between group means
Duncan's multiple range, Tukey's, or Scheffe's test (post hoc measures)