Regression Analysis

Question 1

what is a regression analysis

Answer 1

its a technique to fit a model (mathmatical equation) to data

it can be very simple (few parameters) or complex (many parameters)

Question 2

what is the linear model

Answer 2

simplest model of regression analysis

y - a +bx

this is the equation of a line (regression line)

a and b are the regression coefficients

Question 3

why do we conduct a regression analysis

Answer 3

when we have fitted the equation to the data we know the slope of a relationship between variables

this lets us predict the value for y for a given value of x, or vice versa (extrapolation/interpolation)

Question 4

how do we do regression in SPSS

Answer 4

analyze, regression, linear,

fill in dependent/independent boxes (we must know which way the relationship goes to do this)

click statistics then confidence intervals and estimate

Question 5

discuss multiple regression

Answer 5

for multiple ivs

can tell us how theuy each contribute to the DV and the plane of best fit (3D)

z = ax +by + c

Question 6

how do we do a multiple regression in SPSS

Answer 6

analyze
regression
linear

put 2 in independent box instead of 1

Question 7

can regressions be extended

Answer 7

yes can be extended to any number of variables BUT then becomes extremely difficult to portray the data