Exam 11: Analysis of Quantitative Data

Define the following terms -control variable

Explain how a researcher codes,enters,and cleans data so that it can be used for statistical analysis.What procedures are involved in each of these steps?

Define the following terms -mean

Define the following terms -mode

Is a Type I or Type II error more likely if a 0.05 level is used? Explain.

Define the following terms -correlation

Define the following terms -partials

Describe each of the three measures of central tendency.What are the main differences between them? How are they affected by a normal versus a skewed distribution of data?

Professor Quincy Quacker found a statistically significant relationship between variable X and variable Y.It is statistically significant at the 0.05 level.What does this mean?

Define the following terms -contingency cleaning

Define the following terms -curvilinear relationship

An elementary school teacher has three classes.She finds the following mean and standard deviations for student IQ scores. Mean Standard Deviation Class\#1 106 32 Class\#2 104 9 Class\#3 110 16 She knows she is most effective when the students all have similar IQ levels.Which class is she likely to be most effective with?

Define the following terms -skewed distribution

Define the following terms -cross-tabulation

A researcher wants to express the middle of a distribution of numbers whereby half the cases are higher and half the cases are lower than the middle value.What statistical measure should the researcher use?

Define the following terms -bivariate statistics

Refer to the information in the following table when answering questions 18 to 26: $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\text { Annual Family Income and Education }$ $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\text { Statistics for Three Neighborhoods }$ GLENBROOK MEADOWBROOK ELMBROOK Income Education Income Education Income Education Mean \ 78,000 17 Years \ 28,000 15 Years \ 16,000 11 Years Median \ 27,000 18 \ 28,000 16 \ 18,000 11 Mode \ 26,000 20 \ 28,000 11 \ 12,000 11 Stand Dev. \ 8,000 3 \ 2,000 6 \ 3,000 1.0 (N) (300) (300) (300) $\quad$$\quad$$\quad$$\quad$$\text { * } 4 \text { yrs college }=16 \text { yrs; masters } / \text { law degrees }=18 \mathrm{yrs} ; \mathrm{PhD} / \mathrm{MD} \text { degrees }=20 \mathrm{yrs} \text {. }$ -In which neighbourhood(s)do half the families have incomes of $28,000 or more? $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\text { Annual Family Income and Education }$ $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\text { Statistics for Three Neighborhoods }$ GLENBROOK MEADOWBROOK ELMBROOK Income Education Income Education Income Education Mean \ 78,000 17 Years \ 28,000 15 Years \ 16,000 11 Years Median \ 27,000 18 \ 28,000 16 \ 18,000 11 Mode \ 26,000 20 \ 28,000 11 \ 12,000 11 Stand Dev. \ 8,000 3 \ 2,000 6 \ 3,000 1.0 (N) (300) (300) (300) $\quad$$\quad$$\quad$$\quad$$\text { * } 4 \text { yrs college }=16 \text { yrs; masters } / \text { law degrees }=18 \mathrm{yrs} ; \mathrm{PhD} / \mathrm{MD} \text { degrees }=20 \mathrm{yrs} \text {. }$

Why is knowing the variability or dispersion of a variable as important as knowing its central tendency? How is variation measured?

Define the following terms -cell of a table

What feature of experimental research allows it to demonstrate causality without control variables?