Day 8 Flashcards
(16 cards)
Raw scores and Standard scores
Raw scores- the actual score assigned to an individual on a measure
Standard score- scores that are expressed in deviation units.
Limitaions of raw scores
gives you little info about the position of a score in the distribution.
Z scores
knowing that mean and the standard deviation for a distribution, allows us to locate any score relaitve to the mean. Z scores express in SD units.
Calculating Z scores
to transform raw scores to Z score, subtract mean from the raw score and then devide by the SD.
Understanding Z scores
Tells us whether the scores is aboe or below the mean.
T score
T score uses mean of 50 and SD OF 5
Getting the Pearson (r)
Strength and directions of two variables (if there is one). Significant of statistics now likely or unlikely is what we test. (if they are trustworthy. What is significant?
Understanding correlation
Tells you more than you need to know
Reporting Correlations
The mean, SD to show what was correlated, your correlations and what those correlations show.
Spearman correlation
used when both individual cases are remarked on ordinal scales or their scores we converted to ranks.
Point biserial correlation
Used when one of the two variables are dichotomous
Phi correlation
used when you have both variables are dichotomous.
Liner regression
If we know value of one variable can predict another. Regression analysis is the technique that allows us to make these predictions based on the correlation between x and y.
Terminology
outcome(your criterion variable: y is the variable we are trying to predict. Predictor variable is x use to make prediction.
Linear regression
Equation for straightline= Y: bx+a. B and A are constant, b is slope and describes tilt in line. A value is Y intercept. Value of when x is 0
Least square method
how far on average are the data points from the line? least squares method finds the line that minimize these errors.
