Title: Evaluating Research Claims
1Evaluating Research Claims
2Evaluating TV Ad Claims
- An ad on TV says,
- USE Cocoa Creme. Youll have youthful skin in
10 minutes. All natural ingredients. - You say, Yeah, sure! Youthful skin.
- I bet your face falls off in 10 minutes.
3Evaluating TV Ad Claims
- Another ad tells you to,
- Use Motor Magician. Your engine will purr like
a kitten. And youll get 80 miles per gallon! - You say, I dont want a motor that sounds like
a cat. 80 miles per gallon? HA! Baloney.
4Evaluating TV Ad Claims
- In other words.
- You arent fooled by ads promising what is very
unlikely, and that give no EVIDENCE to support
the inflated promises.
5Evaluating Medical Claims
- The same goes with medicine.
- Lets say your child is ill with an infection.
- The physician says, Heres a prescription for
Megabiotic. - You ask, Will it work, Doctor?
- Physician. Oh, yes. It will fix her right
up. - You. Does it have bad side effects?
- Physician. Oh, no. No side effects.
- You. How do you know, Doctor?
6Evaluating Medical Claims
- How do you know, Doctor?
- That is THE question.
- How do you know?
- What makes you so sure?
- Do you have trustworthy evidence to back up your
claim? -
-
7Evaluating Medical Claims
- Will you let your child take the prescribed
medication if these (below) are the physicians
answers?.... - Well, I and my doctor friends think it works
very well. - In a study of five persons, everyone got well.
- In a study of 1000 persons, many said they felt
much better. - You wouldnt be satisfied by these answers!
- In fact, youd tell the physician, See you
later!
8Evaluating Medical Claims
- What DO you want the physician to tell you?
- How about these?...
- Megabiotic was tested in 10 experimental studies.
- The research was not conducted by the drug
company, but by independent researchers who had
nothing to gain whether Megabiotic was effective
or not effective. - Each study lasted from one to five years.
- Each study had at least 1000 persons in it.
-
More
9Evaluating Medical Claims
- Each study sample had a mix of different kinds of
persons in it younger/older, more ill/less ill,
male/female. - Each study compared the effects of Megabiotic
with other medications (alternative treatments)
and with no treatments (control group). - Each study measured the exact amount of infection
before treatment, each week during treatment, and
at the end of the course of treatment. The
measurement was objective---the amount of
infection in the blood. - Side effects were also measured, such as blood
pressure, skin rash, and kidney function. - More
10Evaluating Medical Claims
- All of the studies found that persons who
received Megabiotic had NO serious side effects.
- Persons who received Megabiotic showed directly
observable (in the blood) reductions in infection
each week until, by the end of one year, 95 of
the persons were cured. - Now would you let your child take the medication?
11Evaluating Medical Claims
- Probably.
- Why?
- Why is the second set of answers from the doctor
convincing? - Think about it.
12Evaluating Medical Claims
- The second answers are more convincing because
- The second answers are more believable.
- The second answers give you solid REASONS to
believe that the medication is likely to cure
your childs infection and not cause harm. - The physician gave you evidence that is hard to
dismiss as just baloney. -
More
13Evaluating Medical Claims
- You cant say, It wont work with my child,
because the research on Megabiotic was tested
with thousands of persons---many of whom were
just like your child. - You cant say, Maybe persons got well by
themselves. It wasnt Megabiotic, because
persons in the control group (who got no
Megabiotic) did NOT get well. - You cant say, They didnt measure improvement,
because in fact they measured what can be SEEN
(the amount of infection in the blood)---an
objective measure of improvement, not an opinion. -
More
14Evaluating Medical Claims
- You cant say, The effects are probably
temporary persons will get sick again, because
some of the studies lasted five years, and no one
got sick again with the infection. - You cant say, The research was rigged to get
good results. For example, researchers dropped
from the study all persons who were NOT getting
well. You cant say this because the drug
company (that wanted the drug to work) did not DO
the research.
15Summary So Far
- Lets summarize.
- What makes research believable?
- What makes the conclusions of research
- The (drug, treatment, or method) is
effective. Therefore, its a good idea to use
it. - so trustworthy that you can be confident in
your decision to use it?
16Summary So Far
- Here is what makes research believable and the
conclusions trustworthy. - The effect of the thing being tested (program,
materials, treatment, or method) is defined and
measured objectively. - The thing being tested is tested against
alternatives (to see which works better) and
against no treatment (to see if the thing works
at all---that is, improvement is much greater
than when there is NO treatment). - The research is done many times (replicated), to
ensure that results are not chance, not a fluke. - The research is done for a long period of time
(longitudinal), to see if the effects are
long-lasting. - More
17Summary So Far
- The research is done with samples of persons who
have the same features as persons in the larger
population who might later receive the program,
treatment, or method. representative sample - The researchers do not have a stake in the
outcomes. independent research
18Lets Apply This to Education
- Just as you feel responsible for the care of
persons you love, you also feel responsible for
the children you teach. - You dont want students to be taught with
curriculum materials or with teaching methods
that dont work and that cause harm---for
example, teaching students the wrong way to read
or to solve math problems. - Therefore, you want to ask tough questions about
research done on curriculum materials and
teaching methods that are advertised, or that a
school district wants you to use, or that your
colleagues say are terrific. - What tough questions should you ask about
research?
19Questions About Purpose. Selling?
- What tough questions should you ask about
research? - Lets say you are reading a research report, or
a description of a new program on a website, or
an advertisement for curriculum materials. - Does the ad, report, or program description sound
as if the authors are selling an idea or a
productto persuade you that they are right that
they have the answer that they can fix schools
and raise achievement? - Just (believe us, join us, buy our
materials). - If selling is their purpose, this is NOT good.
Why? - You can be almost certain that the only data
(evidence) the writers will show are data that
support their claims. They will not show data
that do NOT support their claims. This is
called dishonest.
20Purpose Selling
- In other words, you should be highly suspicious
of their claims about effectiveness. - Our method works.
- Our ideas are sound.
- Use our ideas and program.
- These claims do not come from objective
scientific research. They come from persons and
groups who are making up a story (a sales pitch)
that will get you to buy. - If they had solid research evidence that their
ideas, materials, or procedures were effective,
their writing would not sound like a sales pitch.
21Purpose Reporting
- However, the purpose of a journal article or a
program description may simply be to REPORT the
findings of research. For example, the authors
are telling you what they learned---not what they
want you to believe or to do. -
- For instance, authors may report which one of
three methods of peer tutoring produces the
highest achievement. - Or what percentage of fourth graders are
proficient in reading on grade level after a new
reading program was used. - Simple reporting is good. If authors are not
trying to sell you an idea or materials or
programs, then they are probably going to report
honestly what they found they have nothing to
gain simply by passing on information.
22Questions About the Research Strategy
- There are different KINDS of research questions
for instance, there are questions. - About persons opinions. How do teachers feel
about.? - About what persons do. How do students respond
when teachers.? - About factors that cause or predict changes.
Does timely correction of errors reduce those
same errors happening in the future? - About what is effective. Which program (A, B,
or C) is more effective in raising the reading
achievement of diverse learners? -
23Questions About the Research Strategy
- There are different kinds of research questions,
and there are different kinds of research
strategies---or WAYS of trying to answer the
questions. For instance, there are - Surveys.
- Observation.
- Experimentation.
24Questions About the Research Strategy
- Heres a big idea
- Certain kinds of research questions require
certain research strategies, - or else the research will NOT give evidence
(data, findings) that you can trust. - Do you have high blood pressure?
- Which is the better research strategy to get an
answer you will trust? - Do a survey of the opinions of 20 of your
friends. - Use a blood pressure cuff (every day for a week,
at different times of day) to get exact
measurement. - Blood pressure is NOT an opinion-kind-of-thing!
- It is an objective thing. PRESSURE. Therefore,
it requires an OBJECTIVE measurement---with the
cuff.
25Questions About the Research Strategy
- Here are different kinds of research questions
and the proper research strategies. - What are teachers opinions about a new math
program that they are using? - How well do students think they read three months
after theyve been taught with a new reading
program? - How satisfied are teachers with the supervision
and professional development they receive? - What are the evaluations of parents on the
helpfulness of their childrens teachers? - These are opinion questions.
26Is the Research Strategy Appropriate for the
Research Questions?
- These are opinion questions.
- The researcher wants information on how
teachers, students, and parents SEE things. - Therefore, a useful strategy would be SURVEY
research. - Example of survey research ?
-
27Is the Research Strategy Appropriate for the
Research Questions? Survey Research
- Consider the question on parents satisfaction.
- The researcher selects a sample of families.
- This sample is representative of the whole
population of families of children at schools
for example, small and large families two-parent
and single-parent families families with one
child and families with more children poor
families and affluent families. - Then the researcher either uses a questionnaire
(that parents fill out) or uses interviews
(face-to-face) in which the researcher asks the
same kinds of questions as on the questionnaire
or gives questionnaires to all families and also
interviews a smaller sample to obtain more
detailed information.
28Is the Research Strategy Appropriate for the
Research Questions? Survey Research
- The researcher can examine (analyze) the survey
- information (data) from the questionnaires or
- interviews, and can then determine
- What kinds of help parents feel is adequate.
- What kinds of help parents feel is inadequate.
- What percentage of parents are satisfied vs. not
satisfied with teachers helpfulness. - These findings could assist school administrators
to - improve family-school relations.
29Is the Research Strategy Appropriate for the
Research Questions?
- Here is a different kind of research question.
- What are the different ways that teachers respond
or try to handle students disruptive behavior?
What are the effects of each way? - When students are doing peer tutoring, do
students learn to play the role of tutor and the
role of tutee? If so, what are the behaviors in
these roles? - When a class is organized into learning centers
(e.g., reading, math, science), and students are
allowed to come and go as they wish, what do
students actually DO in the centers?
30Is the Research Strategy Appropriate for the
Research Questions?
- These are questions about what persons
DO---about observable activity---NOT about how
persons see things---their opinions. - Therefore, a useful research strategy is
OBSERVATIONAL research. - Example of observation research?
31Is the Research Strategy Appropriate for the
Research Questions? Observational Research
- Consider the question of how teachers respond to
disruptive - behavior.
- The researcher selects a sample of classrooms.
- Standing out of the way, the researcher takes
running notes (like a sportscaster) on
teacher-student interaction. - After several weeks, the researcher examines the
notes and - a. Identifies different kinds of disruptive
behavior e.g., making noises, talking out of
turn, noncompliance with teacher requests. - b. Identifies how the teacher typically
responds to each kind of disruptive behavior
e.g., telling a student to stop, threatening to
send the student to the office, ignoring the
disruptive behavior but praising students when
they are engaging in desirable behavior. - c. Determining what generally happens when
teachers respond in different ways e.g.,
students do the disruptive behavior more often
vs. less often.
32Is the Research Strategy Appropriate for the
Research Questions?
- Here is yet another kind of research question.
- Is peer tutoring more effective (does it yield
higher achievement) for some subjects than other
subjects? - Are teachers opinions about their new math
programs affected by whether a math program
provides written procedures for teachers to
follow vs. does not provide written procedures
for teachers to follow? - More
33Is the Research Strategy Appropriate for the
Research Questions?
- Under what conditions (e.g., size of school,
recent levels of student achievement, quality of
teaching staff) is it better (there is faster
change, less opposition) when school reform is
rapid and extensive vs. slow and in small steps?
In other words, what factors predict which kind
of school reform works better. - Which math program yields the most math
proficiency in students overall and students by
subgroups, such as ethnicity and social class? - These are questions about causation.
34Is the Research Strategy Appropriate for the
Research Questions?
- These are questions about causation. The idea
- is that
- Certain factors ? Predict or produce
- or variables changes in other
factors
or variables
35Is the Research Strategy Appropriate for the
Research Questions?
- Here are examples of questions about which
factors or - variables predict or produce (cause) effects in
other variables. - Which features of a math program (Teaching
procedures? Practice? How tasks are sequenced?)
have the largest effects on (cause the largest
changes in) learning? - Which features of a school affect (cause or
inhibit) the success of efforts to reform the
school curriculum? - How does subject matter affect (cause or inhibit)
learning through peer tutoring? - Do written procedures or the absence of written
procedures in a math program affect (cause)
teachers opinions of the program? -
36Is the Research Strategy Appropriate for the
Research Questions?
- This kind of question.
- Which factors cause what changes?
- Which curriculum, program, or procedure is more
effective?.... - .requires the strategy of experimental
- research.
37Is the Research Strategy Appropriate for the
Research Questions? Experiment
- The essential feature of the strategy of
experimental - research is that you
- Compare two or more situations (e.g., schools)
that are as similar as you can make them (e.g.,
of students who are poor, size of school, quality
of teaching staff), but these schools are
different in the few factors (e.g., reading
materials) whose effects you are trying to find
out, or test. - If the only main way that the schools differ is
the - reading materials used, and if one school has
consistently - higher reading achievement than the others, then
it is - very likely that the reading materials make the
difference. - What ELSE could it be? After
all. ?
38Is the Research Strategy Appropriate for the
Research Questions? Experiment
- The factor that makes the difference in reading
achievement cant be class size---because this is
the same across all the schools. - The factor that makes the difference in reading
achievement cant be teacher quality---because
this is the same across all the schools. - The factor that makes the difference in reading
achievement cant be the percentage of students
who are poor---because this is the same across
all the schools. - Therefore, the factor that makes the difference
in reading achievement must be the ONE major way
the schools are different----reading curriculum.
39Is the Research Strategy Appropriate for the
Research Questions? Experiment
- However, not all experiments give information
that you can - trust. It depends on how the experiment is
carried out. For - example
- 1. Maybe students in schools with the highest
reading achievement were already reading at a
higher level. Therefore, these students dont
have to learn very much in order to come out
first. In other words, maybe students
pre-skills (and not the curriculum materials)
account for higher achievement. - To rule out this possibility, an experiment
should have pre- - test measures of the variables whose change we
are interested - in. For instance, we should measure reading
skills in all of the - schools BEFORE new reading materials are
introduced, to - see if some classes are ahead of other classes.
40Is the Research Strategy Appropriate for the
Research Questions? Experiment
- So, if an article says that a program or
- method produced more change or is more
- effective than another program or method, ask
- if the researchers did pre-tests to show that
- students all started at the same level. If they
- did not do pre-tests, then you cannot trust the
- claim about effectiveness. The group with the
- highest achievement may have started at a
- higher level.
41Is the Research Strategy Appropriate for the
Research Questions? Experiment
- 2. How do you know how much students learned?
The only way to find out is to do post-tests
(e.g., at the end of the semester and year) to
see where students reading achievement ended up.
And you have to see how much students changed
(learned, achieved) between the pre-test (reading
proficiency at the start) and the post-test
(reading achievement at the end). And you need
to report how much difference there is between
the pre-test and post-test scores. -
- If researchers do NOT do post-tests, or do not
REPORT the - size of differences between the pre-test and
post-test, then you - dont know HOW MUCH students learned as a result
of the - curriculum that was used between the pre-test and
the post- - test. Therefore, you cant trust claims that one
curriculum - produced more achievement than the others.
42Is the Research Strategy Appropriate for the
Research Questions? Experiment
- 3. Were measures objective?
- You dont rely on a physicians subjective
opinion about your - health.
- You look fine to me.
- Maybe the physician is right.
- But what if the physicians opinion is wrong?
- Just so, you want objective evidence of (in this
experiment) - reading achievement. It is nice to know how much
teachers - think their students learned, but you cant judge
- effectiveness based on opinion. Reading is a
real thing. - It can be measured objectively---for example, how
many - words students read correctly per minute.
43Is the Research Strategy Appropriate for the
Research Questions? Experiment
- So, if researchers do NOT use objective measures
of (for example) reading and math achievement
(e.g., counting correct words students read or
problems students solve per minute), but instead
use the subjective opinions of teachers
(Students improved a great deal.) then you
cannot trust claims about effectiveness----because
the researchers did not give evidence of
effectiveness. They only gave evidence of how
teachers see things. But that was not the
question.
44Is the Research Strategy Appropriate for the
Research Questions? Experiment
- 4. Were instruments and measurement methods
tested for validity (they measure what they are
supposed to measure) and reliability (different
persons measuring the same thing would come up
with about the same scores)? - Validity. Do you think a good measure of
reading proficiency is whether students can name
the parts of a book and can turn the pages? -
- If your school principal is selecting a new
reading program, is that the information you want
the principal to use? - Students taught with Weird Phonics learned to
turn the pages. So, Ill use that program with
200 students in my school. - I dont think so.
45Is the Research Strategy Appropriate for the
Research Questions? Experiment
- Turning pages is not what READING means.
- You want to know if a program teaches students
to (1) say the sounds that go with the letters
(2) accurately and quickly read single words (3)
accurately and quickly read passages (4) learn
many new vocabulary words each week (5) answer
both simple and hard comprehension questions
about what they read.
46Is the Research Strategy Appropriate for the
Research Questions? Experiment
- So, if researchers use instruments and measures
that do not measure what they OUGHT to measure,
then the findings have nothing to do with the
research question. - The question is whether a curriculum teaches
students to read. But the findings have to do
with turning pages. Invalid measure. - The question is whether a certain teaching
procedure increases math achievement. But the
findings have to do with how much students
enjoyed being taught with the method. Invalid
measure. - The question is whether peer tutoring is
effective at helping students to spell better.
But the findings have to do with changes in
self-esteem. Invalid measure.
47Is the Research Strategy Appropriate for the
Research Questions? Experiment
- 5. Is the sample size, composition (kinds of
participants), and selection/allocation of
participants to groups appropriate for the type
of study and for how the findings might be used?
- Poor.
- The researcher claims that a teaching method is
effective. However, the method was used in only
one class, or in one school. There is no way to
tell if it would be effective anywhere else. - Poor.
- The researcher claims that a method is not
effective. However, it was used in only one
class, or in one school. There is no way to tell
if it would have been effective elsewhere. - More
48Is the Research Strategy Appropriate for the
Research Questions? Experiment
- Poor.
- The researcher claims that an instructional
procedure or curriculum is more effective than
another. However, the comparison groups (one
class used one curriculum the other class used a
different curriculum) were not created by random
assignment of children to the groups, or by
matching the groups to make sure they had, for
example, the same percentage of boys and girls. - Therefore, the groups may have been different in
other ways besides the curriculum e.g., more
children in one group got reading instruction at
home, and this (not the curriculum) caused
differences in achievement.
More
49Is the Research Strategy Appropriate for the
Research Questions? Experiment
- So, if research involves comparing (for example)
- achievement from one group/sample (class,
- school) to another, but the researchers did NOT
- make sure (through random assignment of
- students to the samples, or through matching)
that - the groups have the same characteristics, then
you - cant trust that differences in achievement are
- caused by the curriculum or teaching method.
50Is the Research Strategy Appropriate for the
Research Questions? Experiment
- Here is one kind of experimental research that
you - DO want to see. Level-1 research.
- The researcher conducts a pilot study to see if a
method - seems to work well enough that it ought to be
given a more - valid test. The researcher uses a small sample
(one class or - school). It is not a representative sample of
the school - population, but that is alright. Do you want to
use a method - that may not work on a lot of kids? The
researcher finds that - the new method is followed by significant student
- achievement. But since the sample is small and
not - representative of the larger school population,
and since - the research was done only once, the researcher
cautions that - the findings are very tentative and cannot be
generalized - anywhere else. Further research is needed.
- This is called honesty.
51Is the Research Strategy Appropriate for the
Research Questions? Experiment
- Here is another kind of experimental research
that you DO - want to see. Level-2 research.
- The researcher repeats research on the same
method in - different schools. Each new study is called a
replication. The - sample of schools is representative of the
population of - schools---small/large, wealthy/poor, rural/urban.
- The researcher claims that data from most of the
studies - show that the method is effective in most of the
schools, but - the researcher cannot figure out which factors
hinder its - effectiveness or what additional factors may be
needed to - make it work better. The researcher advises
caution in using - the method. This is honest and morally
responsible.
52Is the Research Strategy Appropriate for the
Research Questions? Experiment
- Here is yet another kind of experimental research
- that you DO want to see. Level-3 research.
- The researcher conducts a study in several school
- districts at once. The sample of districts is
- representative of the larger population of
schools and - school districts. Three new reading curricula are
- tested against each other. The three curricula
are - randomly assigned to the districts. Objective and
- validated measures of essential reading skills
are - made before the new curricula are introduced
(pre- - test), every two weeks during the use of the
curricula - (progress assessment). and at the end of the year
- (post test, or outcome assessment.
More
53Is the Research Strategy Appropriate for the
Research Questions? Experiment
- At the end of the year, researchers examine the
amount of change in students skills from
pre-test to post-test. They find that curriculum
A produced significantly more achievement (and
objectively high achievement) in all of the
reading skills (compared to achievement produced
by curricula B and C) in 8 out of the 10 schools
in which it was used. The researchers therefore
claim that curriculum A is more likely than the
other curricula to produce high reading
achievement, and that it can be used with at
least modest confidence. However, they say that
more research is needed to determine the school
conditions in which curriculum A works best. - Would you use curriculum A?