Data Analysis A2 (Xxiao:17/10/2021)

BSB123 Data Analysis

Look at t stat – all wrong – copied from somewhere – multiple students all getting it wrong

P and t test – do one

Used population terminology not sample

P-value – what is it?

6

Hypothesis Test

State the Hypotheses in terms of the parameter (µ,σ,p)

Identify the correct probability distribution (t, z, F, χ2)

Identify level of significance

State decision rule clearly

Use either test statistic method (i.e. in terms of t or z etc) or in terms of p-value. Don’t need to do both.

Decision rule must be consistent with hypotheses

Do calculations

Use either Excel to get solutions where available

Do the calculations to get test statistics e.g. tcalc or zcalc

Make the decision in terms of the question

Check if the conditions of the analysis hold – i.e. did you do a valid test

BSB123 Data Analysis

Regression

Conduct a regression analysis to determine which factors affect a students chance of admission. In undertaking the analysis do this in three steps:

Regress all variables and conduct all tests necessary to determine which variables should be included in an optimal model.

Re-estimate your chosen model from a. Interpret all necessary statistics and conduct all necessary tests.

State your estimated equation and interpret the coefficient of the first and last variable you have included. Use the estimated equation to predict the chance of admission for a Male student from Brazil with a CGPA of 8.5, a TOEFL of 110, a GRE of 320, no letter of recommendation, an interview score of 15 and who came from a mid rated (level 3) university which did not require a research project.

(20 Marks)

BSB123 Data Analysis

Regression Process

Consider the explanatory variables to determine which are likely to affect the dependent variable of interest. This can be done by:

Considering the theoretical logic of whether a variable is sensible

Graphing X against Y to see if they are related linearly

Looking at the correlation matrix (multiple regression)

State the model to be estimated including expectations

What is Y, what is X1, X2 etc and what would you expect to be the direction of the relationship

Determine the strength of the relationship

Test separately the overall significance of the model and each of the individual variables included

State and test the assumptions of the model

Clearly articulate which variables are useful or not, and why and then redefine the model using those you believe should be included.

Compare results of new model to old by redoing all previous steps 2 - 6.

Once final model is determined you can state and interpret estimated equation and use it to predict (if required).

BSB123 Data Analysis

Analysis and Summary Report

Last Semester

Write a brief report to management describing what you have found in non-technical language. The report can be no longer than 250 words. Include any recommendation you would like to make about income determination and hiring practices.

Student 1 – Weak Answer

It was determined that GPA is of clear importance as it has an undeniable importance in the determination of income for new and existing employees.

Gender presents an issue as a current social issue is to ensure equal pay for all genders. Our analysis has indicated that the male staff are earning an extra $2000. This is an issue as it doesn’t present the equal pay requirement.

Additionally, it was found that as your staff’s age increases, their salary increases at approximately $770 per year. Furthermore, this is in line with the generally accepted increases in wages as per general wages awards. (Note this student concluded in an earlier question that age was not an important factor!)

Student 2 – Stronger Answer.

There was insufficient evidence to conclude that there is any difference in the performance on the company test between males and females. However, there is evidence to show that despite males not seeming to outperform females, they are paid significantly more (just over $5000). (All statements are consistent with earlier analyses)

What I was looking for

In terms of remuneration there is evidence that males are being paid more than their female counterparts possibly even more than $5000 on average. Other tests have indicated there is no difference in performance between the genders in terms of results on the test and job performance. While other tests have shown that job performance (Test scores), higher degrees and age all effect income (as expected), given there is no difference in job performance this is an area of inequality which needs to be addressed. It does not seem to be a recruitment issue with equal numbers of males and females employed, so it is a remuneration issue.

BSB123 Data Analysis

Hints

Check for consistency. If you do something in regression that overlaps with something you did earlier are the results the same. IF not, does that represent an issue?

If we can’t see how or why you have done something, then we don’t know if you are thinking correctly. Even if you use Excel just show the output or briefly describe what you did.

You have weeks to do this assessment so presentation should be professional and terminology accurate.

This is not a small assessment – it will take time. Don’t leave it until the last weekend.

Use consultation this week and next to ask questions. We won’t answer specific questions on the research report, but you can be clever in how you ask questions which might lead us to give appropriate direction.

A great deal of the work done on the research report will be repeated in the exam. This is a good chance to practice for the major assessment item.

BSB123 Data Analysis

BSB123 Data Analysis

Criteria Grade 7 6 5 4 <4 Weight

KS (1.1): Demonstrate and apply integrated discipline (including technical) knowledge across the broad field of business with depth in one or more core business disciplines

Application of statistical

knowledge

Selects and correctly uses

relevant graphs and statistical

concepts throughout the

report

Selects mostly relevant graphs

and statistical concepts, and

uses them appropriately

throughout the report

Selects mostly relevant graphs

and statistical concepts, but

with occasional inappropriate

use

Selects only a limited range of

relevant graphs and statistical

concepts, with some incorrect

use

Unable to select and use

relevant graphs and

statistical concepts

20%

KS (1.2): Apply technical and technological skills appropriate and effective for real world business purposes and contexts

Analysis of data

Analysis methods appropriate

for comprehensively and

critically investigating the

research question were

selected; all analyses and

calculations were correctly

performed

Appropriate analysis methods

were selected

comprehensively investigating

most aspects of the research

question ; most analyses and

calculations were correctly

performed

Analysis methods relevant to

some aspects of the research

question were selected,

though narrowly addressing

the research question ; most

analyses and calculations

were correctly performed

though minor errors are

present

Some analysis methods

relevant to the research

question were selected,

though minimally addressing

the research question ;

substantive errors are evident

in the analysis and/or

calculations

Analysis methods were not

appropriately selected or

were not relevant to the

research question; multiple

major errors present in

analysis and/or calculations

50%

HO (2.1): Exercise independent judgment and initiative in adapting and applying knowledge and skills for effective p lanning, problem solving and decision making in diverse contexts

Interpretation and

explanation of research

findings

Results are presented clearly

and interpreted correctly and

comprehensively; research

findings are critically

discussed in depth and are

coherently related to all

aspects of the analysis and

research problem

Results are presented clearly

and interpreted correctly in

some detail; research findings

are well discussed in detail in

relation to most parts of the

analysis and research problem

Results are mostly presented

clearly, though minor errors

of interpretation are evident;

research findings are well

discussed in relation to some

aspects of the analysis and

research problem, though

explanation is lacking in detail

in parts

Some results have been

presented and interpreted

correctly though substantive

errors in explanation and/or

interpretation are present;

research findings do not

sufficiently address the

research question and/or

analysis, and contain minimal

explanation

Little or no attempt to

present or interpret results,

or attempt contains major

interpretation errors;

research findings lack

relevance to the analysis

and/or research question

and are provided with little

or no explanation

20%

PC (3.1): Use information literacy skills, and communicate effectively and professionally in written forms and using media appropriate for diverse purposes and contexts

Written expression and

integration of relevant

statistical findings

Writes fluently and clearly

using language, format, and

structure that always adheres

to the report genre; meaning

is clearly articulated and

effectively expressed, and

relevant to task

Language is generally fluent

and clear; format and

structure mostly appropriate

for the report genre; meaning

is effectively expressed and

relevant to task

Writes generally fluently with

occasional grammatical errors;

format and structure not

always appropriate for report

genre; meaning generally clear

and relevant to task but lacks

clarity in parts

Meaning is apparent but not

clearly and fluently expressed,

with limited relevance to the

task; format and structure not

always appropriate for the

report genre

Meaning is confusing or

mostly irrelevant to task with

frequent grammatical errors;

format/structure

inappropriate for the report

genre (or not meeting proper

academic standard, e.g.

plagiarism)

10%