DAY 2:
DATA ANALYSIS
Rohit
rorohit@mix.wvu.edu
August 19, 2015
1
BEFORE YOU START…
• Read the Background Information.
– Gives you an introduction to the problem.
– May give hints useful for the Analysis Questions.
• Read the Problem Statement.
– It will give you an idea of what your results should provide.
• Read the instructions for the entire project.
– What you need to do in a later step might impact how you
want to complete an earlier step.
• Read the Analysis Questions carefully.
– Generally, you’ll figure out the data you need to answer
them as you complete the project. It helps to know before
what you should be looking for.
2
ABOUT THE ANALYSIS
QUESTIONS
• Analysis Questions will ask you to identify patterns
or trends in the data used in the project.
• You might also be asked to explain why something
occurred.
• Your answers should be:
– 2-3 sentences, generally.
– Give some rationale for your answer. Not just yes/no.
• Your answers might come from:
– Data in the project
– Your own existing knowledge
– Internet
3
SAMPLE ANALYSIS QUESTIONS
Population by Age Groups
35%
29%
30%
Percentage of Population
Suppose you have the
data shown in the chart
to the right and are
asked:
• West Virginia’s
population growth
hasn’t kept pace with
the U.S. average.
Why might this be the
case?
25%
27%
25%
24%
26%
21%
20%
16%
15%
13%
WV
US
10%
9%
10%
5%
0%
0-18
18-24
25-44
45-64
Age Group
65+
4
SAMPLE ANALYSIS QUESTIONS:
LOOKING FOR ANSWERS
Population by Age Groups
35%
29%
30%
Percentage of Population
Notice about the data:
• People age 45+ make
up 6% more of WV’s
population than the
national average.
Apply common
knowledge:
• Few babies are born
to people 45 or older.
25%
27%
25%
24%
26%
21%
20%
16%
15%
13%
WV
US
10%
9%
10%
5%
0%
0-18
18-24
25-44
45-64
Age Group
65+
5
SAMPLE ANALYSIS QUESTIONS:
GIVING AN ANSWER
A good Analysis Question answer would be:
• West Virginia’s population is older than the
national average. With fewer people in
their child-bearing years, there are fewer
new births to help grow the population.
6
WHAT DOES IT MEAN?
90%
Grades
85%
80%
Sec. 1
75%
Sec. 2
70%
Sec. 3
65%
• What is your graph
telling you about the
grades for Section 1?
• What does it mean
that Section 2’s line is
sloping downward?
• What could this graph
tell you about the
study habits, the
course instructors, or
attendance?
7
INTERPRETING YOUR GRAPHS
• Locate the specific area to which the question is referring.
– In the previous example, the first question asks about Section 1.
Looking at the lines for Sections 2 and 3 won’t tell you much about the
first section’s performance.
• Charts give you a visual representation of your data. Know how
chart presents its data.
– Here, line is showing a decrease in test scores across the semester.
• The visual results are only part of the answer. It can tell you what
happened, but might not tell you why. Use the Internet. Think about
possible causes. Draw on personal experience.
– In the section whose grades increased, study habits could have
improved, students might have started attending class after getting a
first low grade, or the instructor could have changed his or her teaching
style.
– The opposite reasons could apply to the section whose grades
decreased.
8
CHECKING YOUR WORK
• Make sure your answers make sense.
– Look for numbers that are implausible, like negative
gasoline prices
– Check that your results are consistent across the project
• Review your analysis question answers
– Verify your analysis question answers agree with data
– Consider if your rationale makes logical sense
• Use hints in the project instructions.
– Access queries will tell you how many records should
result
– If you’re told to format 5 rows and get 10 rows of data, you
probably did something wrong
9
THINK OF YOUR GRADE…
Remember:
Analysis Questions are worth
20% of your project grade.
Always answer them!
10