Day 10 – Team C
Today we started with the revision of Dicriminant with Bank
loan file. It is an imperative
tool in SPSS that helps in the prediction of the outcome. It can thus have a
descriptive or a predictive objective.
Discriminant
function analysis is used to determine which continuous variables discriminate
between two or more naturally occurring groups. For example, a researcher may
want to investigate which variables discriminate between fruits eaten by (1)
primates, (2) birds, or (3) squirrels. For that purpose, the researcher could
collect data on numerous fruit characteristics of those species eaten by each
of the animal groups. Most fruits will naturally fall into one of the three
categories. Discriminant analysis could then be used to determine which
variables are the best predictors of whether a fruit will be eaten by birds,
primates, or squirrels.
We follow the following procedure:
Analysis-> Classify-> discriminant
·
Select grouping variable as default.
·
Select rest as independent.
·
Select means in statistics and summary table in
classify.
·
Save with all 3 option checked.
Go to the data view, we observe 4 new columns added, which
signifies:
1.
Dis_1: What we predicted
2.
Dis1_1: Scores
3.
Dis1_2: Probability of not defaulting
4.
Dis2_2: Probability of defaulting
Now, in the output file we compare canonical discriminant
function table with functions at group centroids table to see the effect of
various variables on grouping variable.
Then we studied the Gss93 file. Choose respondent sex as the
independent variable, while music type as independent. Follow similar steps
like before and save file also. In the output file we compare canonical
discriminant function table with functions at group centroids table to see the
effect of various variables on grouping variable.
Second half of the class was covered under Conjoint topic.
It is a method to find what people actually want. Here we use several
combination of opinion answers, and ask people to rate them and provide ranking
to them. Based on this we calculate their preference for an individual aspect
(using highest utility difference).
The objective of conjoint analysis is to determine what
combination of a limited number of attributes is most influential on respondent
choice or decision making. A controlled set of potential products or services
is shown to respondents and by analyzing how they make preferences between
these products, the implicit valuation of the individual elements making up the
product or service can be determined. These implicit valuations (utilities or
part-worths) can be used to create market models that estimate market share,
revenue and even profitability of new designs.
Advantages:
§ Estimates
psychological tradeoffs that consumers make when evaluating several attributes
together.
§ measures preferences
at the individual level
§ uncovers real or
hidden drivers which may not be apparent to the respondent themselves
§ realistic choice or
shopping task
§ able to use physical
objects
§ if appropriately
designed, the ability to model interactions between attributes can be used to
develop needs based segmentation
Disadvantages:
§ designing conjoint
studies can be complex
§ with too many
options, respondents resort to simplification strategies
§ difficult to use for
product positioning research because there is no procedure for converting
perceptions about actual features to perceptions about a reduced set of
underlying features
§ respondents are
unable to articulate attitudes toward new categories, or may feel forced to
think about issues they would otherwise not give much thought to
§ poorly designed
studies may over-value emotional/preference variables and undervalue concrete
variables
§ does not take into
account the number items per purchase so it can give a poor reading of market
share
Then we use SPSS and go to: (food priority example)
Data-> Orthogonal designs-> Generate
Start adding factor name eg type and add. Click on type and
define values with lables and continue. Click file when you are done with all
factors and click save. Now for ranking:
Data-> Orthogonal designs-> Display
Select all apart from status and card. Select, listing and
profile, and OK. You will receive a card table, copy paste in excel and give
ranking as per your preference. 1-16 ranks, with 1 being most preferable and 16
meaning least.
Next part will be followed in the next class.
Rahat S. Dhir
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