• The use of telephone directory as a sampling frame results in three major sources of bias: exclusion of non-telephone households, exclusion of telephone numbers that are issued after the publication of the telephone directory, and exclusion of unlisted numbers.
• Earlier research, mainly in the United States, into bias resulting from using telephone directories as sampling frames, focused on the characteristics of telephone owners and non- telephone owners. Leuthold and Scheele (1971) found that people living in rural areas and those on low incomes were less likely to own telephones than those living in urban areas with higher incomes. Tyebjee (1979) found this difference in telephone ownership often resulted in over-representation of households with certain geographic and demographic characteristics when telephone directories were used as sampling frames. Hyett and Allan (1976) also noted that the telephone owners were more affluent than the general population.
• Some of this bias is attributable to out-of-date listings. Cooper (1964) estimated that the proportion of subscribers not listed in the telephone directory at the end of the year amounted to 18% in United States. Blankenship (1977a) estimated that if 20% of families move annually, then the average listings of non-current names will be around 10%.
• A major source of bias in recent times is the increasing use of unlisted telephone numbers. Leuthold and Scheele (1971) found that 9% of their respondents had unlisted telephone numbers. Brunner and Brunner (1971) and Frankel and Frankel (1977) questioned whether the characteristics of the unlisted telephone owners are different from listed telephone owners.
• Cooper (1964) stated that persons whose numbers are unlisted may represent, at least in part, higher income levels and greater educational accomplishment, such as lawyers, physicians, entertainers and other public personalities. In contrast, Leuthold and Scheele (1971) found that unlisted numbers average income and education levels were similar for listed and unlisted populations.
• Moberg (1982) stated that if unlisted numbers are systematically excluded, the resulting sample would consist of people somewhat older, more rural, more white, more educated, more retired and more white collar than the households with telephone service.
randomly selecting a naturally-occurring group of subjects from a larger target population.
- In cluster sampling, naturally occurring groups of subjects, rather than individual subjects, are randomly selected for participation in research. For instance, if a researcher wants to use elementary school students in an educational study, he or she could randomly choose a school from the schools in his state, and use all the students in that school as participants in the study. That's cluster sampling. A variation of cluster sampling, known as multistage cluster sampling, involves selecting a large cluster -group- and then selecting selectively smaller clusters. For example, the researcher studying elementary school students could randomly select a school district, then randomly select a school from the chosen school district, and then randomly select a classroom from the chosen school. In this case, both forms of cluster sampling would be more practical than the alternative of simple random sampling. That would involve randomly selecting individual elementary school students from across the state.
Perceptions of reality:
Quantitative: Ethnic minorities share similar experiences within the public social service system. These experiences can be described objectively; that is, a single reality exist outside any one person.
Qualitative: Individual and ethnic group experiences within the public social service system are unique. There experiences can only be described subjectively: that is, a single and unique reality exists within each person.
2. Ways of "knowing":
Quantitative: The experience of ethnic minorities within public social services is made known by closely examining specific parts of their experiences. Scientific principles, rules, and test of sound reasoning are used to guide the research process.
Qualitative: The experience of ethnic minorities within the public social services is made known by capturing the whole experiences of a few cases. Parts of their experiences are considered only in relation to the whole of them. Sources of knowledge are illustrated through stories, diagrams, and pictures that are shared by the people with their unique life experiences.
3. Value Bases:
Quantitative: The researchers suspend all their values related to ethnic minorities and social services from the steps taken within the research study. The research participant "deposits" data, which are screened, organized, and analyzed by the researchers who do not attribute any personal meaning to the research participants or to the data they provide.
Qualitative: The research is the research process, and any person values, beliefs, and experiences of the research will influence the research process. The researcher learns from the research participants, and their interaction is mutual.
Quantitative: Research results are generalized to the population from which the sample is draw (e.g., other minority groups, other social services programs). The research findings tell us, on the average the experience that ethnic minorities have within the public social service system.
Qualitative: Research results tell a story of a few individuals' or one group's experience within the public social service system. The research findings provide n in-depth understanding of a few people. The life context of each research participant is key to understanding the stories he or she tells.
o Highest level of measurement.
o Used to measure variables whose attributes are based on a true zero point.
o E.g.: How many children one has, Income, How many times one has seen a social worker, length of residence in a given place, age, number of times married, number of organizations belongs to, number of antisocial behaviors, number of case reviews, number of training sessions, number of supervisory meetings.