Population and sampling frame

The population in this research context refers to tourism/hospitality and wine businesses in the nineteen parishes that comprise the geographical area in this research (as explained in Chapter 1). As described in the introductory chapter, the wine and tourism industries are considered as potentially complementary as the creation of wine tourism related offers can potentially contribute to the development and promotion of regions. However, and although it seems evident that wine and tourism businesses in the Douro Valley should engage into cooperation initiatives (given its potential positive outcomes), there is no evidence of such option being put into practice, and this may be hindering businesses development and success.

The tourism/hospitality industry businesses taken into consideration in the current study were: accommodation (hotels and rural tourism establishments), restaurants and leisure businesses. Those businesses that might be considered as being intermediaries (travel agencies and tour operators) were not taken into account in this study. The identification of these categories was facilitated by the fact that

there were lists of the number of businesses provided by both industries organisations. A list of the different categories of businesses was obtained in early September of 2009 from the national tourism governmental organisation, Turismo de Portugal, and also the Regional Tourism Authorities and Municipalities, as indicated in Table 4.1.

Table 4.1: How information of tourism businesses was obtained

Categories of Tourism

businesses How lists of businesses were obtained

Accommodation

List provided by the Regional Tourism Organisation (Turismo do Douro)

Rural tourism

establishments

List provided by the Regional Tourism Organisation (Turismo do Douro)

Restaurants

List provided by the Regional Tourism Organisation – Turismo do Douro, but it did not include all the municipalities. Thus, For the missing municipalities in the list, municipalities’ sites were checked. Tourism section and links to restaurants were chosen to identify the restaurants recommended to visitors. Chinese and Pizza Restaurants were not included because they were not considered as regional traditional gastronomy restaurants.

Leisure Businesses

List provided by the National Tourism Organization (Turismo de Portugal). In this case, only those businesses established in one of the 19 municipalities of comprising the selected region were considered in this study. The reason for this choice has to do with the main aim of this study.

Source: Author

With regard to wine businesses, two categories of business can be found in the Douro, namely wine producers, and wine producers and bottlers. The latter were selected to be part of the current study. These businesses produce wine from fresh grapes grown entirely on his/her vineyard or from partially fermented grape must, assuming sole responsibility of the bottled wine.

With regard to wine businesses in the Douro Valley and for the purposes of this research, wine producers and bottlers were chosen to be part of this study. These wine businesses were classified by the researcher as ‘Quintas’ and they refer to those businesses that produce, bottle and sell their products in the market. This name was adopted in this study mainly for two reasons. First, it was the name

mostly used by the respondents when referring to wine producers and bottlers.

Second, this name was also used in order to not contribute to any confusion when it comes to the legal classifications of wine businesses used in Portugal. The population of wine businesses considered in this study is comprised by 259 businesses in total.

In relation to wine businesses, the information about the categories and the number of businesses was provided by Institute of Vine and Wine (IVV). This institute is responsible for coordinating and monitoring the institutional organization of the wine sector, auditing the system of quality certification, monitoring European Union policy, and preparing rules for its implementation, and participating in the coordination of the promotion of wine in overseas markets (IVV 2012) Additionally, a list of businesses that produced table and Port wine in the region was provided by the inter-professional public institute, IVDP, the Port and Douro Wines Institute.

4.8.2. Sampling

Sampling is the process of selecting a proportion or a subset of the population (Pizam 1994; Bryman 2004). A sample is always viewed as an approximation of the population, rather than a whole in itself (Pizam 1994).

The purpose of studying and understanding the sample and its characteristics was to generalize its characteristics and to draw conclusions that would generalize to the population of interest (Finn et al. 2000, Sekaran 2003). Thus, choosing an appropriate sample through a sampling method, and minimizing errors (Pizam 1994) was of paramount importance in this research.

Considering that there are different categories, or strata, within tourism businesses in this research (accommodation, rural accommodation, restaurants and leisure businesses), the population of this type of businesses was sampled through stratified random sampling. In relation to wine businesses, as all the businesses in

the sample operate in much the same way, there was therefore no need to separate them out into strata.

With regard to tourism businesses, the strata used for sampling were the different categories of tourism businesses. Stratified random sampling involves a process of stratification of businesses into exclusive categories, followed by random selection of subjects from each population (Pizam 1994; Sekaran 2003; Bryman 2004;

Sarantakos 2005). Stratified sampling was adopted in this research because, as stated by Finn et al. (2000) and Bryman (2004), information regarding the businesses based on the selected criteria was available. In addition, stratified random sampling was adopted to ensure that the sample drawn from the population under a study was as representative as possible in terms of characteristics of that population that were important to the study (Clark et al. 1998). With stratified sampling, the resulting sample is distributed in the same way as the population in terms of the stratifying criteria (Bryman 2004). Also, each important stratum of the population is better represented (O’Leary 2004), and more valuable and discriminated information is obtained with respect to each stratum (Sekaran 2003).

Stratified sampling is used when a stratum of interest is a small percentage of the population and random processes could miss it by chance. By using stratified sample, no stratum is left aside (Neuman 2006). Also, using a stratified sample

“makes more likely that cases are evenly selected from all the strata, thus reducing the possibility that the sample is disproportionately concentrated on one part of the population” (Malleta 2006, p. 3). In general, “stratified sampling produces samples that are more representative of the population than simple random sampling if the stratum information is accurate” (Neuman 2006, p. 231).

Within each stratum of tourism businesses a systemic random process was adopted to guarantee that every unit in the sampling frame for that strata has an equal, calculable and non-zero probability of being included in the sample (Oppenheim 1992; Finn et al. 2000; Sekaran 2003; Bryman 2004, Sarantakos 2005, Saunders et al. 2007). With regard to wine businesses, a systemic sampling method was used with regard to the businesses in the sample.

For wine and tourism businesses to be selected from the sampling frame the same sampling method was used, namely sampling intervals (Neuman 2006). To calculate the sampling interval, the next procedures were followed. First, each business was given a number. Secondly, and having determined the sample size (that will be presented in the next section), the total number of businesses in the sampling frame (for each category in the case of tourism businesses) was divided by the sample size, to give the interval progression n. Finally, every n^th business in the obtained list of businesses (explained in the previous section) after the randomly chose staring point was then chosen. If the selected respondent was not available for inclusion in the study, the next one in line was selected. The sample size of tourism and wine businesses is presented and explained next.