Mobile phones and Telephone Survey Methods

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Mobile phones and Telephone Survey Methods

• Vesa Kuusela
• Statistics Finland

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Outline

• Change of telephone coverage in Finland
• Survey practice at Statistics Finland
• Non-sampling effects of mobile phones
• Sampling related effects of mobile phones
• Concluding remarks

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Characteristics of Mobile phones in Finland

• Respondents do not pay for incoming calls if
  phone is in Finland
• Most mobile phones in Finland are privately own
• practically none prepaid subscriptions
• Most mobile phones are listed
• People are 'expected' to have a mobile phone
• 90 of people aged 15 45 years call daily
• over 65 of people aged 15 30 send text
  messages (SMS) daily
• Some users are very young
• Mobile phone is personal appliance (wrist watch)
• Mobile phone is also private

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Change of Telephone Coverage in Finland

• Fixed phone coverage has decreased since 1993
• July, 1999 mobile phone coverage exceeded fixed
  phones
• Fixed phones are replaced by mobile phones
• Probably trends continue similarly
• Change is different in population segments

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Structure of Telephone Coverage

• Total telephone coverage is over 99
• Fixed phone coverage 64
• Mobile phone coverage is 93 of households and c.
  94 of people
• In some population groups everyone has a mobile
  phone
• 47 of households have more than one mobile phone
  (74 if one person households are excluded)
• Great variation between population groups

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Change of Telephone Coverage by Type of the
Household
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Survey practice

• Fixed phone is preferred
• More than half of the telephone interviews are
  conducted via mobile phone
• Calls to mobile phones
• Ask always if interviewing is appropriate
• What, if respondent is (e.g.)
• abroad?
• driving car?
• in a noisy place?
• Other mobile phones in household?

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Non-sampling effects

• Length of interview
• No prominent difference
• Differences in subject matters
• Mode effect is difficult to study because phone
  types are so segregated in population
• Probably there are no differences
• Non-response
• In regular surveys non-response rates decrease
• Telephone (catalogue frame) surveys ?
• Telephone expenses
• In Finland, over 40 increase in three years

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Sampling related problems (1)

• Mobile and fixed phones are unevenly distributed
  in population segments
• Profile of mobile phone users
• Young very young people have mobile phones
• Own, rented or employers phone?
• Household or personal survey?
• Fixed phones make a household sample
• Mobile phones make a personal sample
• How to interview all members of a household

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Sampling related problems (2)

• Area sampling is not possible
• Frame coverage
• Under coverage if either of phone types left out
• Over coverage if both phone types are included
• Inclusion probabilities in catalogue frame
  surveys
• Big families (with mobile phones)have higher
  inclusion probabilities
• Intracluster correlation?

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Concluding remarks

• Speech communication may move mainly to mobile
  phones
• Structure of telephone coverage is not know in
  many countries
• Surveys expenses rise
• Survey practices have to be redefined
• Method research is needed especially for
  catalogue frame surveys
• More profound changes may be ahead

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Mobile SMS research Questionnaire Dialogue
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Mobile (txt messaging) Research

• Present Future Great complementary research
  tool for short targeted surveys, with the new
  mobile technologies far reaching possibilities
• SMS Research Experiences
• Text Messaging dialogue can extend up to 5-7
  questions, longer surveys need to split/rotated
• Very rapid response (in 10 minutes 80 of data
  collected)
• Highly cost efficient
• Positive respondent feedback (Italy, Germany, UK,
  Finland) and in some cases above average response
  rates (10-45)
• So far used for research purposes with a defined
  target group (and available list) such as mobile
  marketing effectiveness, mobile services research
  - RDD research to be tested