1 Introduction
1.1 Objectives
The broad objectives of the research were to determine:
- how many televisions, computers and mobile phones are in the average household
- how often people are replacing these items
- what households do with these types of electronic equipment when they come to the end of their useful lives
- how many items are being held in storage
- what households know about safe disposal of these items
- what prevents households from disposing of these items.
1.2 Method
The results in this report are based on questions asked in a UMR Research nationwide omnibus survey. This was a telephone survey of a nationally representative sample of 750 New Zealanders, 18 years of age and over. Fieldwork was conducted from 26 to 31 January 2006 at UMR Research's national interview facility in Auckland.
The sample
Telephone numbers for those included in the sample were sourced from the Telecom White Pages.
The sample universe was stratified into 23 telephone directory regions. The number of residential addresses in each of these regions was determined, and a quota was specified for the proportion of the sample that must fall in each region. Table 1 shows the percentage of respondents for each area and the number of respondents to be surveyed in each area for the sample of 750 respondents.
Table 1: Stratified sample, by telephone region
|
Directory region
|
Geographic region
|
Percentage
|
Sample size
|
|---|---|---|---|
|
01 |
Auckland 1 |
5.1% |
38 |
|
02 |
Auckland 2 |
4.1% |
31 |
|
03 |
Auckland 3 |
7.4% |
55 |
|
04 |
Auckland 4 |
7.4% |
55 |
|
05 |
Auckland 5 |
4.5% |
34 |
|
06 |
Auckland 6 |
2.1% |
16 |
|
07 |
Bay of Plenty |
7.1% |
53 |
|
08 |
Christchurch |
12.3% |
92 |
|
09 |
Gisborne |
1.0% |
7 |
|
10 |
Hawke's Bay |
4.0% |
30 |
|
11 |
Manawatu |
3.6% |
27 |
|
12 |
Marlborough |
1.2% |
9 |
|
13 |
Nelson & Bays |
2.5% |
19 |
|
14 |
Northland |
3.4% |
25 |
|
15 |
Otago |
4.7% |
35 |
|
16 |
Southland |
2.7% |
20 |
|
17 |
Taranaki |
2.8% |
21 |
|
18 |
Timaru & Oamaru |
2.2% |
17 |
|
19 |
Waikato |
8.1% |
61 |
|
20 |
Wairarapa |
1.3% |
10 |
|
21 |
Wanganui |
1.6% |
12 |
|
22 |
Wellington |
10.3% |
77 |
|
23 |
West Coast |
0.9% |
6 |
| Total | 100% |
750 | |
The telephone sampling scheme
The random sample of telephone numbers was generated from all number ranges found in the Telecom White Pages for New Zealand. Random digit dialling was conducted off this sample so that unlisted numbers were captured in the sample.
To limit the sample frame to private households with telephones, the following types of telephone numbers were filtered out from the sample:
- Telecom Yellow Pages
- disconnected or fax lines
- where the interviewer determined the contact was not a private household
- business lines.
Margin of error
The margin of error for a 50 percent figure at the 95 percent confidence level for the sample of 750 is plus or minus 3.58 percent.
Call-back and calling times
Up to five call-backs were made to initially selected respondents to ensure that non-response had a minimal impact on the representativeness of the sample. Appointments were made to ring back respondents if the time they were first contacted was not convenient.
Respondents were called between 5.30 pm and 9.00 pm during the week, between 9.30 am and 6.00 pm on Saturday, and between 9.30 am and 9.00 pm on Sunday.
Response rate and weighting regime
The response rate for this sample was 36 percent.
The survey data were rim weighted by age, sex and household size. Rim weighting calculates weights using a form of regression analysis. This requires two parameters: a limit, which defines how close the weighting procedure must get to the targets that have been set in order for the weights to be acceptable, and a number of iterations, which defines the number of times the weight calculations may be repeated in order to reach the cell targets.
Rim weighting is designed to weight characteristics simultaneously. The rim weighting process achieves all the desired proportions while distorting each variable as little as possible.
Statistical definitions
Some household calculations are included in this report and are based on information sourced from Statistics New Zealand.
The total number of households used in calculations (1,553,000 households) was sourced from Projected Households 2006 (Assuming medium fertility, medium mortality, medium migration and 'B' living arrangement types) - National Family and Household Projections: 2001 (base) - 2021 Update.
Regional household statistics were sourced from Projected Households by Regional Council Area 2006 (Assuming medium fertility, medium mortality, medium migration and 'B' living arrangement types) − Subnational Family and Household Projections: 2001 (base) - 2021 Update.
