Research Paper Examples
How many letters on average does the average SJC student
have in his or her last name? How about the first name? My
claim is that the average for both is 7 letters. Your goal
is to test this claim and decide whether or not it is
plausible. You are to do a statistical analysis and report
your finding both numerically and in the form of a short
Among the issues you will need to confront are:
How can you get a random sample of students? Each student
must have an equal chance of being selected. I suggest using
random numbers generated by Excel with the student
directory. I explained an acceptable way of getting the
sample in class. You must explain exactly how you drew your
sample in your paper. If the sample is not taken correctly,
then the results will mean nothing.
You should also explain why not all students are listed
in the directly, and try to justify why the omission of some
students is unlikely to alter the results.
After you get a sample of 25 (which is a very small
sample, but we are more interested in showing the procedure
than finding an accurate estimate), you need to compute a
test statistic, which will be not a z-score but a t-score.
You can follow the example in the textbook on page 337 to do
this. Then you need to explain clearly what your results
show you in words that would make sense to someone who has
never taken a statistics class.
You will quickly discover that the hard part of this
assignment is taking the sample. The rest should be fairly
easy, even the writing up of results.
If you have any questions, ask.
(For many years I required students to do a paper in
which they took a random sample of books from the library to
determine the average age of the library books. Sometimes
this was an assignment of estimation; here it is presented
as an assignment in hypothesis testing. Early on they could
do a systematic random sample using the card catalog that
contained paper cards. Then the library discarded the paper
and went digital, and they could use the record numbers.
Then the library changed their database system and I could
never again figure out a simple way to have the students
take a random sample, so the assignment died. It is given
here as an example of something that can (or could) be done
in an introductory course.)
Jack and Joan had an argument last week about the age of
the books in the college library. Jack, knowing only enough
about statistics to be dangerous, decided to settle the
argument by sampling. He went to the library's economics
section, where all the really good books hang out, and took
a sample of nine books that happened to be sitting on the
shelf. From this he assumed that the average age of books in
the library was 26 years old.
Joan was dubious about this claim, and thought that the
way Jack took the sample might lead to questionable results.
She asked a professor to settle this dispute. Upon hearing
this story, the professor exclaimed, "What a wonderful
assignment for my class. I will have them test the
hypothesis that the average age of books in the library is
The above story is mostly fictitious. The part that is
not fictitious is the part about the assignment. You are to
test the claim discussed above by taking a random sample of
50 books from the SJC library. You need to find a way to
take a random sample, and the following may be of some
All the books in the library have a record number that
you can find in the following way. Start with the main
screen (the one which has the crude picture of the building)
on the on-line catalog and hit return. This takes you to a
search screen. Now press the Find key. This gives you an
expanded search list that most people do not know exists.
(In fact this is Library Top Secret (LTS) and unspeakable
things can happen to those who pass this secret on to those
who are not authorized for LTSs.) Use the arrow key to get
to the RN Record Number item. Then enter a record number.
All record numbers at SJC are between 1-1 and 1-138290.
However, included in these numbers are some items that are
not books (records, for example) and some items that no
longer have a book assigned because the book has been
discarded. When you enter the record number of a book, you
will get information about the book, including the year in
which the book was published.
Your assignment is to take random sample of 50 books
using random numbers generated by SPSS. (Look at Chapter 1
in the text and the second lab worksheet.) Then, using SPSS
test the hypothesis that the true mean age of library books
is 26 years. After you are finished, you are to write up
your results in a three or four page paper that clearly
explains exactly what you did (including especially how you
got your sample) and what the results mean. Include as an
appendix printed results from SPSS.