Selecting equivalent samples in cross-cultural psychology.

The selection of comparative and representative samples is difficult in cross-cultural research because of the complexity of the variables studied and for the practical reasons that random samples are less accessible. Literacy rates and educational levels vary between societies and that heterogeneity may become a confounding factor in the response patterns of the participants. Further, the influence from travel and contacts that are by-products of a globalized world make it nearly impossible to obtain pure culturally influenced responses in today’s world.

For practical reasons culture refer in many cross-cultural studies to the country of origin of the respondents. In effect cross-national studies often replace cross-cultural research. This imprecise definition defeats equivalence since as we noted in chapter 1 different ethnic groups and cultures can co-exist within a nation. In any event in cross-national studies care should be taken not to assume national homogeneity as even countries with intact traditions and stable socio-economic systems may in fact be very heterogeneous in ethnicity. The obvious solution is to obtain matched samples from the cultures studied. However, when matching for one variable that very psychometric control often causes mismatching on other salient factors. For example being Black in South Africa does not mean the same as being Black in London since these matched samples may differ on variety of socio-economic variables and matching for race would not produce equivalence.

The sample selected represents a larger population. To ensure that outcome researchers have in the past examined issues related to appropriate sample selection. Probably in most cases samples are chosen for convenience, typically by the availability of university students in many societies. Convenience sampling has often been criticized as being unrepresentative of the population for the obvious reasons of the higher level of education and socio-economic standing of university students (Wintre, North, & Sugar, 2001). However, whether university samples are useful in comparative research is really an empirical issue to be investigated by comparing university students and representative samples (Ellsworth & Gonzales, 2007) and not dismissed without evidence. Pernice, Van der Veer, Ommundsen and Larsen (2008) demonstrated that university students could be successfully utilized in both concept development and scale construction in an attitude toward immigrants study in New Zealand. Students in this study based their attitudes on the same criteria as the general population supporting the affect of shared cultural and political systems in both student and population samples.

Another type of sampling is called systematic since samples are selected based on some theory. Perhaps the objective is to study the effect of membership in religious organizations, and samples are drawn with proper controls from particular religious groups in different cultures. Another study may investigate the treatment of homosexuals in different cultures and select accordingly. The underlying theory might be the affect of religious dogmatism as related to tolerance.

In random sampling an effort is made to obtain representative sampling of the population studied. Random sampling is representative, and the results obtained are assumed to represent the population studied with little error. In random samples each individual has an equal and independent chance of being selected, and if the sample size is large enough the results are reliable and the population characteristics are represented with relative little error (Offerman & Hellman, 1997). In general the larger the number of participants the less the sample will vary from the population characteristics (Heiman, 1996). The ideal in cross-cultural sampling is to utilize the random selection of participants. As noted that is often difficult or impossible, and convenience samples are frequently used. Although convenience sampling may not produce bias in the development of assessment instruments, the researcher must be cautious in generalizing the results of the study to the overall population of the culture.

Several sampling decisions have to be made when comparing cross-cultural groups. The primary decision is what cultural groups should be compared. That conclusion might in turn be based on some theory that predicts differences on the variables of interest. Secondly, all cultures have subsets of groups that vary on important dimensions. Therefore a second consideration is what sub groups should be included. Finally, the issue of how to select individual respondents must be considered.

Finally, in cross-cultural research the interest is not just to achieve representative samples, but also in ensuring equivalent samples. In practice this requires control for equivalence on demographic factors including socio-economic status, occupation, religion or ideology, age and sex. For example it would not be useful to compare a university sample from the United States with a sample drawn from Aboriginal fringe dwellers in Australia, since among many differences there would be obviously confounding educational and socio-economic effects. Demographic factors must therefore be controlled when comparing across cultures. However, even controlling for demographic variables may not provide proper comparative controls since for example being old in Japan or Europe may be very different experiences.

Date: 2015-01-11; view: 919