4. Who does the NFA ask?

4.1 Strategies for selecting a representative sample

Policy makers need constant feedback on whether their policy interventions are effective. The NFA has the potential to provide such feedback to policy makers, but the usefulness of the NFA interview data information for public policy depends on the ability of the NFA to capture the benefits of forest use to distinct groups of people in society. To be able to produce national aggregates of the main benefits of forest use to specific categories of users, it is necessary to structure the data gathering process according to both users and their respective uses in each site. Once the categories of users have been defined, representatives from each of these groups and key informants are interviewed to document the characteristics of their forest use.

There are different ways of categorizing user groups, and each country needs to define the criteria that make the most sense for its particular policy concerns. One possible way of defining user groups is to divide them according to their legal rights to harvest the product or service in question. The suggested format in Annex 1 offers one possible typology for such a classification, but for some countries it may be more appropriate to stratify according to ethnic groups, gender, age, or family income. Whichever classification is used, the information gathered through interviews will seek to capture the nature of the relationship between different users and forest resources.

The selection of who to interview is a critical step for securing data quality. In rural areas, there are often a wide variety of different user groups and each group has its own interest in tree and forest resources. Given the great diversity among these groups¿ characteristics and interests, a representative sample of this complexity would need to include a significant number of observations in order to reflect this reality.

Once a consultant has carried out a number of interviews with different forest users in a number of sites, the project is faced with the question whether the completed interviews are significantly representative. This may be the most difficult question of all in the NFA interview process. The difficulty lies in the fact that the NFA seeks to produce data that are representative of forest use only at the national level, not at each site, or even sub-national levels. This means that it is virtually impossible to determine the adequate sample size for each site until a very large proportion of the permanent plots have already been completed. By then, it is very costly to return to earlier locations to carry out more interviews. Moreover, the complexity of forest user-relationships to forests are likely to vary a great deal from one site to another, makes it inappropriate and inefficient for the NFA to require field crews to complete the same number of interviews in all sites. Ideally, the NFA team should invest its resources to interview more users in complex sites and fewer users in sites with less complexity (fewer users and more homogenous usage). To address this dilemma, it is suggested that the NFA team employs a triangulation-based, adaptive sampling method.

4.1.1 Adaptive sampling of Interviewees

An adaptive sampling approach allows the NFA teams to adjust the number of interviewees according to the variation of forest use characteristics in each site. This approach promises to improve both the accuracy and efficiency of the NFA interview component.

Key to the accuracy aspect of this sampling approach is the process of triangulation, also known as cross-checking. Triangulation is a way to ensure that the results of a study are as valid and unbiased as possible. Triangulation can be an effective way of addressing bias as it strives to look at any particular issue from as many perspectives as possible, but at least three (Freudenberger, 1995).

NFA personnel are advised to take the following steps to decide who and how many individuals should be interviewed in each site:

  • A local key informer is interviewed to establish who the different local forestry actors are (forest users and forestry stakeholders).
  • As a rule of thumb, the NFA field personnel should interview at least ten percent of the number of identified forest users within each site. This means that for a forest plot that is used by 80 household members, interviewers should talk to at least 8 forest users and key informants.
  • The minimum number of interviewees in all sites is three actors, of which at least one individual should be a woman.
  • The interviewees should be identified with regards to their different interest in the tree and forest resources associated with the particular land use category.
  • In each plot (250 x 20 m), consultants should interview the selected actors, making sure the selection includes at least:
    • One of the landowners, or users of the land, within the plot (if there are no private landowners in the plot, interview the person living closest to the plot area);
    • One local person who has detailed knowledge of the different forest uses by different local groups and individuals (if no such person can be identified, interview a local person who is familiar with forest use in the general area of the plot but with no formal connections to the landowner - remember that their interest in the resource must be different from the land owners).
    • A civil servant responsible for the monitoring and enforcement of the forestry regulations and laws in the area and who knows the particular forests surveyed (if there is no such person available, interview a technical officer in the municipal government administration who knows the particular area, or ask this person for a reference to more knowledgeable local people).

  • Each interview should not focus exclusively on the forest use by the particular ¿interest group¿ interviewed, but should cover forest use in general, including the use by other individuals of which the interviewee has knowledge.
  • Interviews should be carried out according to the guidelines on interview techniques presented in the section How does the NFA ask?.
  • Once the perspectives of the different individuals with distinct interests have been interviewed, the NFA interview team meets to compare notes and to triangulate the data gathered through the interviews.
  • During the meeting, the kinds of products and goods used from the plot are listed alongside the groups that use the specified goods and the specific questions for each group of users are listed.
  • Before the forms are filled out, possible discrepancies on specific answers to questions on the forms are identified by triangulating the information gathered from the distinct actors.
  • If no discrepancies exist among interview data sources, the forms may be filled out, carefully documenting the information provided by the interviewed actors.
  • If important discrepancies exist in the data collected through interviews, additional actors need to be interviewed. These actors may be identified among
    • Other landowners not already interviewed;
    • Individuals working for local non-governmental organizations;
    • Neighbours to the landowners;
    • Employees of the municipal government who live in the area and who know about forest uses in the area;
    • Individuals who have carried out studies or research in the area;
    • Individuals who happen to be present in the tract when bio-physical information is obtained;
    • Commercial intermediaries dealing with tree and forest products;
    • Local helpers contracted to help out in the bio-physical inventory;

  • The conversation in these additional interviews is focused primarily on the items that are subject to discrepancies from previous interviews.
  • Finally, the team meets anew to triangulate the information from the additional interviews and if consensus is reached on the previously disputed answers, the forms are filled out for the plot.
last updated:  Wednesday, February 2, 2005