Title: Assoc. Prof. Sami Fethi
1Department of Business Administration
SPRING 2009-10
The Research Design and Measurements
- by
- Assoc. Prof. Sami Fethi
2The Research Design and Measurements
- The design problem
- Problem structure and research design
- The problem of cause
- The classic experiment
- Validity threats
- Defining measurement
- Scales of measurement
- validity and reliability in measurements
- Improving your measurements
3The Research Design and Measurements
- Research design
- Research designs are master techniques
(Kornhauser and Lazarsfeld, 1955). - The research design is the overall plan for
relating the conceptual research problem to
relevant and practicable empirical research as
well as data collection and its analysis. - The design problem
- Empirical research is conducted to answer (or
elucidate) research questions . - Poorly formulated research questions will lead to
misguided research design. - An open approach with no research questions is a
way of research design, however it is very risky
approach (Hammersley and atkinson, 1995). - Strategic choice of research design should come
up with an approach that allows for solving the
research problem in the best possible way within
the given constraints. - e.g. Time, budgetary and skill constraints.
- Choice of research design can be conceived as the
overall strategy to get the information wanted.
This choice influences the subsequent research
activities as such data and its analysis-servant
techniques (Kornhauser and Lazarsfeld, 1955). - When the design problem is neglected, such errors
called design error occurred as well as
irrelevant design choices.
4Problem structure and research design
- Structured and Unstructured
- A political party wants to conduct a poll to
examine its share of voters. This is a structured
problem because the political party knows what
information is wanted, that is, the percentage of
voters. Descriptive-structured. - Company As sales have dropped in the last two
months and the management does not know why. The
management does know what has caused the decline
in sales. This is a more unstructured problem.
Explanatory-unstructured. - An advertising company has produced two set of
copy and wants to know which is the most
effective in an advertising campaign. This case
is structured and may produce some effect-cause.
Causal-structured. - Explanatory research
- When the research problem is badly understood,
more or less explanatory research design is
adequate. - Flexibility is a key characteristic of the
explanatory research to solving the problem. - e.g. Detective TV series start with phone call
that somebody is murdered who did this who is
the quilty person how does th edetective
proceed s/he tries to collect data and find a
lead as new information comes up, the picture
becomes clearer and finally the detective found
answer. - Explanatory research requires skills, but key
requirements are often the ability to observe,
get information and construct explanation.
5Problem structure and research design
- Descriptive research
- In such research, the problem is structured and
well understood. - e.g. Examine the case where a firm wants to look
at the size of market M. First step is to make a
classification of what is meant by market. Such
as specify the potential group of buyers, a
specific area and a specified time period. - Having defined group, (say X) and time (say one
year), the researchers task now is to produce
this information by conducting a survey if
relevant secondary data is not available-
sampling plan-beyond this point is to construct
question that is measurements. - Key characteristics of descriptive research are
structure, precise rules and procedures. - In the following figure, a researcher wants to
describe smokers by social class, i.e.
Cross-table.
6Cross-table
Table 1Â Cross-table
7Problem structure and research design
- Causal research
- In this case, the problem under scrutiny are
structured, however in contrast to descriptive
research, the researcher is also confronted with
cause-effect problems. - In a such research the main tasks are to isolate
causes and tell whether and to what extent causes
results in effects. - e.g. Is the medical drug effective? What dose is
the most effective? Does the advertising help in
acheaving greater market share? See the following
example for the case of causal research.
8Weight loss programme
Groups Groups Groups Groups Groups
Diet Exercise Education Control
Weight loss -5.2 kg -4.1 kg -6.1 kg -1.5 kg
Stadard deviation 2.3 1.5 3.5 1.2
participant 30 30 30 30
Table 2 The data show that groups on average
have lost weight but the diet, exercise and
education groups lost more than the control
group. Here diet, exercise and education are
seen as potential causes of weight loss
9The Problem of Cause
- Cause
- A dealer has reduced the price of TV sets by 10
percent and sales increased by 20 percent. Is the
price reduction a cause of the increased sales? - Manager are often preoccupied with success
factors. Peters and waterman (1982) claimed that
being close to the customers is an important
factor in explainning success. Is closeness to
customers a cause of success? - In order to analyse the relationship between
cause and effect, we need to use the covariation
technique. - In such framework, price reduction and change
sales or price reduction and closeness to
customers. - In the following table, effect is not always
present when cause is present. i.e. 80 of cases
with price reduction, no increase in sales occur.
(see Table 3). i.e. alternative causes.
10Covariation
Table 3 Â Covariation
11The importance of theory
- Cause-effect
- The question of cause-effect also calls for a
priori theory in research. - The need for theory can be illustrated in the
following way. Assume that you have two variables
(X and Y) in your research and the relationships
will be possible as below - e.g. X?Y (X cause Y)
- X?Y (Y cause X)
- X?Y (mutual causation)
- X ? Y (no relationship)
- The use or role of theory are roughly stated by
March and Simon (1958). The use or role of theory
are multiple in research and include the
following - identifying research problems
- raising questions
- identifying relevant factors and relationships
i.e. Variables - interpreting observations or data
- advancing explanations
12The classic experiment
- Experiment
- Even though most business studies are not
experimental as we cannot control organizational
behaviour, the classic experimental research
design is useful for understanding all other
designs. - In the following figure, O denote observations, X
is the experimental stimulus. Observation are
made both before (pre-test) and after
manupulation of experimental stimulus
(post-test). Two groups are included, the
experimental group and control group and R
indicates randomization. - e.g. Some treatment such as medical drug for
headache. - Here independent variable is the experimental
stimulus and experimental variable treatment
takes values 1 and 0 respectively. - The researcher has control over the independent
variable so s/he can manipulate the various
experimental conditions. The impact of outside
factors is assumed to be levelled out through
randomization. - Do we need to use control group?
- We need such a group to evaulate whether the
drug has any effect or not.
13The Problem of Cause the classic experiment
Figure 1Â The classic experiment
14The case of influenza
- Influenza
- In this case, 100 people diagnosed with influenza
were randomly assigned to two groups, a test
group that was an effective drug and a control
group which was given ineffective one. After one
week, asked Do you feel better? - In the following table. A higher fraction of the
test group reported better than is the case for
control group. In other word, it is very likely
the drug has an effect. - In the case, the treatment is considered a cause
or the effective medical drug really can be seen
as a cause of improvement. - More people receiving the treatment feel better
than those who did not.
15Reported improvement in the testand control
groups
Table 3Â Reported improvement in the test and
control groups
16The effects of message and gender
- Type of message and gender
- The independent (explanatory) variable can
definitely more than two values. - e.g. Whether selling strategies is most
effective or not, they can be labelled as
s1-phone call, s2-advertisement, s3-personal
selling, s4-(per ads). - More than one independent (explanatory) variable
(treatment) can be included - e.g. Selling message using either one-sided or
two-sided arguments and another variable is
gender that is whether the salesperson is a woman
(1) or a man (2). In this case, it is also
possible to capture interaction effect as such
(60-50)10 and (50-40)10 so no intercaction
effect is present (see Table 4).
17The effects of message and gender
Table 4Â The effects of message and gender
18Validity threats
- Validity
- The researcher wants to obtain valid knowledge,
that is, wants results that are true. - e.g. If a study shows that advertisement A is
more effective than advertisement B, the
researcher should be confident that this is the
case (see Scase and Goffee, 1989). - There are mainly two types of validity (1)
internal validity, (2) external validity. (1)
This is the question of whether the results
obtained within the study are true. (2) It refers
to the question of whether the findings can be
generalized. - There are mainly four type of threats to
validity (1) history, (2) maturation, (3) test
effect, (4) selection bias (see Cook and
Campell,1979). - e.g. (1)- Tv store ?reduce price 10 ? sales
increase 20 ? next month? ? potential external
threat. (2) patients without treatment ?what is
the cause of the patients recovery ? the medical
drug or their immune system? (3) the test itself
may affect the observed response ?work with
specific programme ? whether thier performance is
caused by the programme or the fact that they use
thier skills. (4) when the subjects are not
assigned randomly ?advertisements questions for
cigarettes.
19Selection bias
- Advertisement
- In the following table selection bias can be
observed well. - e.g. It could be argued that 20 percent of those
who have seen the advertisement bought while only
5 percent of those did not see the advertisement
bought. Thus the ads has contributed 15 percent
(20-5). - Is the observed findings valid? It may be, but
the result may equally well be explained by the
other factors as such preferences or selective
perception..
20Selection Bias
Table 5Â Reading of advertisement and purchase
21Other Designs
- Other designs
- When researchers want to study relationships
such as organizational size and innovativeness,
gender and career, they cannot easily manipulate
size of organization or gender. Thus the research
designs can be applied in the following way - Cross-sectional design
- In Table 5, deviates from the classical
experiment in several ways. There is no control
group or randomization. The cause (advertisement
reading and effect (purchase) variables are also
measured at the same time. This is a
cross-sectional research design. - e.g. In table 5, the researcher is confronted
with several tasks in order to prove that ads may
cause purchase. Here, it may be control for
another variable for the potential effect of
other factors. In table 6, innovativeness is
higher in large organization than smaller ones.
Here, industry may be an explanatory factor. In
table 7, the control variable may be type of
industry and size seems that does not have any
effect. - In cross-sectional research, data on independent
and dependent variables are gathered at the same
point in time. - Time series
- Data on independent and dependent variables are
gathered over time. The researcher empirically
investigate whether independent variable(s) can
explain dependent variable.
22Innovativeness byorganizational size
Table 6Â Innovativeness by organizational size
23Control for third variable
Table 7Â Control for third variable
24Measurement
- Defining measurement- GIGO (garbage in garbage
out) - Problems to be studied in business research are
almost endless. Studies are empirical implying
the gathering use of data so empirical studies
always implies measurements. - Measurement can be defined as rules for
assigning numbers to empirical properties.
Numbers enabling the use of mathematical and
statistical techniques for descriptive,
explanatory and predictive purposes which may
reveal new information about the items studied. - In everyday life, we all make use of
measurement for example a beauty contest can
be conceived as some sort of measurement. A key
element here is the mapping of some properties. - e.g. measurement can be defined in the follwing
format race can be coded such as white1,
black2, Hispanic3, other4. This assignment
means mapping and illustrated in figure 1. In the
figure, gender are mapped into 1 (Women) and 0
(men).
25Defining Measurement
Figure 1 Mapping (assignment)
26Objects, properties and indicators
- Measuring object or properties
- In fact we do not measure objects or phenomena,
rather we measure specific properties of the
object or phenomena - e.g. A medical doctor may be interested in
measuring properties such as height, weight or
blood pressure. - To map such properties, we use indicators, that
is the scores obtained by using our operational
definitions for example responses to a
questionnaire (see fig 2).
27Object/phenomenon, properties and indicators
Figure 2 Object/phenomenon, properties and
indicators
28Levels (scales) of measurement
- Levels or scales
- In empirical research, distinctions are often
made between different levels of measurement or
scales of measurement. - Nominal level (scale) This is the lowest level
of measurement. At this level numbers are used to
classify objects or observations. - e.g. It is possible to classify a population
into females (1) and male (0). Also the same
population can be classified according to place
of living as such 1city center, 2south, 3
north, 4east, and 5west. - Ordinal level (scale) Some variables are not
only classifiable, but also exhibit some kind of
relationship, allowing for rank order. - e.g. If we do not know the exact number or
distance between , for example, A and B or A
greater than B, we can construct such as the
following scale. In the following case, B is more
satisfied than A, but we cannot say that how much
more satisfied. - e.g. Very A
B Very - dissatisfied -3
3
satisfied
29Levels (scales) of measurement
- Internal Level
- when we know that the exact distance between
each observations and this distance is constant,
then an interval level measurement has been
achieved. This means that the difference can be
compared. - i.e. One should be compared to another one, the
temperature rises from 80 C to 100 C. - Ratio Level.
- The ratio scale differs from an interval scale
and with a ratio scale, we can the comparison of
absolute magnitude of numbers is legitimate. - i.e. A person weighing 200 pounds is said to be
twice as heavy as one weighing 100 pounds. - see Table 8 for more information about the
properties of the measurement scales.
30Scales of Measurement
Table 8 Scales of measurement
31Validity and Reliability in Measurement
- Random error
- Measurements often contain errors so when we
measure something, we want valid measures. In
order to clarify the notions of validity and
reliability in measurement, let us focus on the
following equation - X0XTXSXR
- Where, X0 is observed score, XT is true score, XS
is systematic bias and XR is random error. - In a valid measure the observed score should be
equal to or close to the true score. Valid
measures presume reliability and random error is
modest. Reliability refers to the stability of
the measure. - e.g. A boys true height is 175 and scale
somehow measures 170. This tells us that a valid
measure also is reliable, but a reliable measure
does not need to be valid. The difference is
assumed to be random error or component and if
random error is higher than expected that measure
is neither valid nor reliable. - The following figure (3) illustrates how random
measurement errors may influence the findings.
i.e. r XY 0.8 x 0.5 x 0.5 0.2.
32Validity and Reliability in Measurement Random
Errors
In this case, unobserved cc between X and Y is
0.8. The cc between concept and obtained measure
for X and Y is 0.5 and the observed relationship
(cc) is 0.2.
Figure 3 Random errors
33Multiple indicators
- Multiple indicators
- Multiple indicators are often used to capture a
given construct. For example, attitudes are often
measured by multiple items combined into a scale.
- The main reason for using multiple indicators is
to create measurement that covers the domain of
the construct which it purports to measure.
Random error in measurement is reduced. - e.g. Crohnbachs a is often reported because
this is a measure of the intercorrelations
between the various indicators used to capture
the underlying construct. - Construct validity.
- It can be defined as the extent to which an
operationalization measures the concept which it
claims to measure. (Zaltman et al., 197744) - It is necessary for meanningful and
interpretable research findings can be assessed
in the following ways. - Face validity (1), convergent validity (2),
divergent validity (3). - (1) to what extent the measure used seems
resonable, (2) to what extent multiple measure of
multiple methods for measuring the same construct
yield similar results, (3) to what extent a
construct is distinguishable from another
construct.
34Two methods, two constructs
Table 9 reports the CC for X and Y by the two
method are 0.82 and 0.79 respectively. As CC for
the same construct measured by different methods
are high and substantially higher than any
between construct CC, it is reasonable to assume
convergent valitidy.
Table 9 Two methods, two constructs
35Improving your measurements
- Improving your measurements
- Elaborate the conceptual definitions
- Develope operational definitions (measurement)
- Correct and redefine measurement
- Pre-test the measures for their reliability
- Use the final measurement instrument