These slides offer dissertation help in the form of a discussion on the various considerations involved in issues of population and sample size for dissertations.

1. FOCUS ON
POPULATION &
SAMPLE
Justifying what you do during your
doctoral research
Slides and video by:
www.doctoralnet.com

2. Confused about the
issue of population
vs sample in your
dissertation study?
1. What is it all about?
2. Why is it important?
3. Where do you start?

3. CONSIDER:
Regarding how you slice out population:
 Who is affected by the issues/challenges or problems around which your
study revolves?
 How much area does your study cover?
 What is the demographic make up of that group in that area?
 Are there any particular considerations that make them special or unique
from the wider diversity that surround them?
 Will the effect of the outcome of your study on this group be direct or indirect?
Merely of interest or will it create policy?
 If policy, who will the policy affect directly and indirectly
In comparison to….
 Who can you get your hands on/get IRB permission to ask questions of,
through which you will develop your results?
 To what extent does the smaller group you will ask questions of, mirror the
larger group who may be affected?

4. Your Sample
Population that
are affected by
the issue
Population that
would be
interested

5. Your classroom will be studied
and mirrors the population of the
district/state in this manner…..
Your district/state are
especially concerned
because…..
The United
States/much of the
world studies the
affect of testing on
students

6. Your Sample
1) It is your task to convince your
readers that your sample is indicative
Variable A
of the population to whom you claim
your study to be of interest.
2) To the extent that your study is
focused on multiple variables, you
need to convince your audience that
your sample contains them to the
Variable Variable
same likelihood or % as the wider B C
population from which they are
derived.

7. Your Sample
1. Relationships may not be Students Defined
apparent as is seen here
2. All relationships/demographics
to be At-Risk
need to be sorted out
3. In order to believe that the
sample is correct for the
Who
population Reportin are at
g Test risk of
Anxiety failure

8. AS YOU CAN SEE…
The sample here is NOT the
same As the sample here….
Variable Students
A Defined to be
At-Risk
Reporting Who are
Variabl Variabl Test at risk of
eB eC Anxiety failure

9. Question:
Can you draw out each relationship
and describe them?
Are they convincing?
How large is the full population as
compared to the sample you can
easily question?
Is it convincing to believe that
answers from your small group will
represent the larger group as well?

10. TYPE OF SAMPLE &
MAKING A CASE FOR SIGNIFICANCE
Convenience Random
 Easy to obtain  Must meet the standard that
 Credibility of results depends everyone a) in a larger but
on your convincing your accurately distributed sample
reader that your sample b) had an equal likelihood to
equated to a large degree participate
with the population from
which they were drawn.  Credibility depends on your
random controls and means of
 The closer to that population
the more likely that credibility obtaining your sample
can be established population
 Statistical likelihood that a
random sample will represent
the whole

11. Draw a convincing
discussion of population
/sample and…
• You will have a much easier time
to demonstrate your work is
credible, and reliable.
• Your committee will have smaller
number of challenges before you
can move forward
• Your work will have a greater
likelihood of being picked up
later/have greater affect on your
field

12. For More Information
1. Doctoral Net Academy (DNA) a
self guided way through the maze
of writing a dissertation with
regular opportunities to ask
question of live advisors
2. Finishing Faster Groups adding
accountability and support to the
DNA mix
3. Both virtual and luxury retreats
taking you away and offering still
greater one on one support