Research Class 8 Part 2

In ___ statistics, the focus is to describe relationships between two variables, under two different levels of measurement conditions

bivariate

There are two types of bivariate analyses, each of which is based upon the level of ___ of the two variables.

measure

If two variables are categorical, then the bivariate descriptive statistics is a ___, called a pivot table in Microsoft Excel.

contingency table

If two variables are continuous, then the bivariate descriptive statistics is a ___

correlation

A ___ variable is a variable that can take on one of a limited, and usually fixed, number of possible values

categorical

___ variable is a type of categorical data that does not possess any quantitative value nor inherent ordering

Nominal

___ data is where the variables have ordered categories and the distances between the categories are not known

Ordinal

___ variables are defined as variables that can assume an infinite number of values within a given range

Continuous

An ___ scale is one where there is order and the difference between two values is meaningful. No true zero exists

interval

A ___ variable, has all the properties of an interval variable, and also has a clear definition of 0

ratio

In a contingency table, both variables (IV and DV) are ___, either nominal or ordinal

categorical

Bivariate descriptive statistics for categorical data can only include ___ for the cross tabulation of two variables, because the level of measure puts the attributes or elements of a variable into discrete groups

frequency counts and percentages of scores

The tally or ___ is the calculation of how many people fit into a certain category or the number of times a characteristic occurs

frequency count

In a contingency table, there are rows and columns for the variables.

The ___ variables are loaded in the columns

independent

The ___ variables are loaded in the rows.

dependent

A ___ is the combined frequency data per group from each variable e.g. the frequency of women who are also non-smokers.

cell

If two variables are continuous variables, then their bivariate descriptive analysis is the ___.

correlation

A correlation describes the ___ between two variables that are interval or ratio levels of measure with respect to the strength and direction of the relationship.

relationship

The bivariate descriptive statistics for two continuous variables ask the question…

What is the direction of the relationship between the two variables and how strong is the relationship?

Scores (X and Y) are represented either in a table, or on a ___.

scatterplot

X is on the ___ axis

horizontal

Y is on the ___ axis

vertical

Three ___ describe a correlation: direction, form, and strength.

characteristics

The ___ of a relationship can be described as either positive or negative.

direction

This is created by the scatterplot plot of the points where a straight line is formed. The line is not always straight.

the form

This measures how strong the relationship is. It measures how well the data fits the specific form (e.g., a linear correlation measures how well the data points fit on a straight line).

the degree

A ___ correlation is always. +1.00 or –1.00

perfect

This indicates a perfect fit. A correlation of ___ indicates no fit at all.

0

Numerical values between + 1 and –1 reflect the degree to which there is a ___, predictable relationship between the two variables.

consistent

The most common correlation measures the degree and the direction of the linear relationship between two variables and is called the ___

Pearson correlation

Pearson correlation is identified by the letter ___

r

How is the strength of this correlation described? (0.62)

moderate

Correlations infer that two variables are ___ to each other; they do not explain why (it does not measure causation – the IV does NOT cause the DV – it precedes the DV and so is related).

related

There is one more very important descriptive number for a correlation: it is called the correlation coefficient of ___.

determination

The ___ of the correlation is measured from 0–1.

strength

But, that does not explain how much of the ___ (variance) in the outcome DV variable (Y) can be accounted for by the amount of change (variance) in the independent variable (X).

change

If the correlation number is ___, it will calculate the proportion of the variance in the DV that is explained by the proportion of variance in the IV, which is called the correlation coefficient of determination

squared

you can graph ___ variables with histograms or polygons

continuous

A researcher can also graph relationships between two variables. This is called a ___

regression line

A regression line defines the ___, one-to-one relationship between each X value and its corresponding Y value.

precise

It identifies the ___ (central tendency) of the relationship and can be used for prediction.

center

The regression line reflects the best ___ as to the score on the Y variable would be predicted by a score on the X variable.

estimate

A linear relationship between X and Y variables can be expressed by the equation…

Y = bX + a

b and a are fixed ___ (that determine the slope).

constants

The value b is called the ___. (Determines how much the Y variable will change when X is changed by one point)

slope

The value of a is called the ___ because it determines the value of Y when X = 0. (On a graph, the “a” value is the point where the line intercepts the Y-axis)

Y-intercept

The ___ is the calculation that creates the line of prediction. It determines how well a line fits the data points.

least-squares solution