• Their principal use is twofold:1. Within organizations, the collection, analysisg , , y

and dissemination of these data ensuringensuringthatthat theythey havehave aa positivepositive experienceexperience withwithyy pp ppthethe company’scompany’s goodsgoods andand servicesservices.

2 Although sales or market share can indicate2. Although sales or market share can indicatehow well a firm is performing currently,satisfactionsatisfaction isis anan indicatorindicator ofof howhow manymanysatisfactionsatisfaction isis anan indicatorindicator ofof howhow manymanycustomerscustomers willwill makemake furtherfurther purchasespurchases ininthethe futurefuturethethe futurefuture.

• There are various ways to obtain customer feedback with regard to their satisfaction glevels with the product(s) and the company Some of them arecompany. Some of them are,–– Telephone followTelephone follow‐‐upup

ll dd–– Customer Customer complaint complaint datadata–– Direct Direct customer customer visitsvisits–– Customer Customer advisory advisory councilscouncils–– User conferencesUser conferencesUser conferencesUser conferences

Th th th d t th• There are three common methods to gather surveydata: face‐to‐face interviews, telephone interviews,and mailed questionnaires.

• The personalpersonal interviewinterview methodmethod requires theinterviewer to ask questions based on a prepre‐‐structuredstructuredquestionnairequestionnaire and toto recordrecord thethe answersanswersquestionnairequestionnaire and toto recordrecord thethe answersanswers.

•• TelephoneTelephone interviewsinterviews are less expensive than face‐to‐face interviews. These can be monitoredmonitored by the

hh tt t th t th ifi d i t iresearchresearch teamteam to ensure that the specified interviewprocedure is followed.

• The mailedmailed questionnairequestionnaire is lessless expensiveexpensive. However,The mailedmailed questionnairequestionnaire is lessless expensiveexpensive. However,this savings is usually at the expense of responseresponse ratesrates.

Face‐to‐Face Telephone Interview MailedFace‐to‐FaceInterview

Telephone Interview Mailed Questionnaire 

Gives very high Less expensive and special Very Lessdegree of validityof the data

methods needed to increaseefficiency.

Expensive butmore chancesfor low responseprate.

The majorlimitations are

The limitations of thismethod are the lack of direct

Questionnairedevelopmentlimitations are

costs and factorsconcerning thei i

method are the lack of directobservation, the lack of usingexhibits for explanation, andh li i d f i l

developmentrequiresprofessionalk l d dinterviewer. the limited group of potential

respondents—those who canbe reached by telephone.

knowledge andexperience andshould be dealtwith accordingly.

Survey

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ed bility

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h of 

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ype of S

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Spee

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In Person – – + – + – + – ++ ++ + + ++Phone + + ++ + + – – – +Mail ++ – – – – – – + + – –++ + + 

– = Disadvantage – – = Worst+     = Advantage ++   = Bestg+ – = Could be an Advantage or a Disadvantage

Wh th tt bb ii ll it i tt tltl tt• When the customercustomer basebase isis largelarge, it is tootoo costlycostly totosurveysurvey allall customerscustomers.

• Estimating the satisfaction level of the entireEstimating the satisfaction level of the entirecustomer population through a representativerepresentativesamplesample isis moremore efficientefficient.

• To do that ScientificScientific probabilityprobability samplingsampling methodsmethodsare used.

• There are four basic types of probability sampling• There are four basic types of probability sampling:–– SimpleSimple RandomRandom SamplingSampling–– SystematicSystematic SamplingSamplingSystematicSystematic SamplingSampling–– StratifiedStratified SamplingSampling–– ClusterCluster SamplingSampling..

I t ti li i l d• In systematic sampling one simply goes down alist taking every kth individual, starting with arandomly selected case among the first ky g findividuals.

• Systematic sampling is simpler than randomli if li t i t l l lsampling if a list is extremely long or a large

sample is to be drawn.• However there are two types of situations inHowever, there are two types of situations inwhich systematic sampling may introduce biases:– (1) The entries on the list may have been ordered sothat a trend occurs and

– (2) the list may possess some cyclical characteristicthat coincides with the k value.that coincides with the k value.

I t tifi d l fi t• In a stratified sample, we first , and 

. • The strata are usually based on important variables 

t i i t th t f i t tpertaining to the parameter of interest.• Stratified sampling, when properly designed, is more efficient than simple random sampling andmore efficient than simple random sampling and systematic sampling.

• Stratified samples can be designed to yield greater p g y gaccuracy for the same cost, or for the same accuracy with less cost.

I t tifi d li l ithi h• In stratified sampling we sample within each stratum. Sometimes it is advantageous to divide the 

. • A cluster sample is a simple random sample in 

hi h h li it i l t f l twhich each sampling unit is a cluster of elements. • Usually geographical units such as 

.• Cluster sampling is generally less efficient than p g g ysimple random sampling, but it is 

.

H l l i ffi i t?• How large a sample is sufficient?• The answer to this question

andand.

• The higher the level of confidence we want fromThe higher the level of confidence we want fromthe sample estimate, and the smaller the errormargin, , and viceversaversa.

• For each probability sampling method,,,

some of which (such as that for cluster sampling)are quite complicated.

• The following formula is for 

(e.g., percent satisfied) based on :

)1(2 ppNZn −×=

on  :

)]1([ 22 ppZNBn

−×+=

N – Population SizeZ – Z Statistic from normal distributionP – Estimated Satisfaction Level

for 80% Confidence Level, Z = 1.28for 85% Confidence Level, Z = 1.45for 90% Confidence Level, Z = 1.65

B – Margin of Error for 95% Confidence Level, Z = 1.96

h fi i i f i l (• The five‐point satisfaction scale (very satisfied, satisfied, neutral, dissatisfied, and very dissatisfied) is often used in customer satisfaction surveys. 

• The data are usually summarized in terms of percent satisfied. p

• In presentation, run charts or bar charts to show the trend of percent satisfied areshow the trend of percent satisfied are often used.