Bridging the Gap: linking timber trade with infrastructural ...

south bank (1270 m 3 ). Therefore, the estimated number of planks traveling over the ferry would have
been vastly underestimated had data been recorded from the south bank only. This underlines the
importance of having more than one individual collecting data at each location to enable crosschecking.
Further, it is important to make a detailed analysis of these data, down to the level of individual vehicles
crossing the ferry. After detailed comparison of the data collected from both sides of the Ndundu ferry
crossing, it can be seen that whilst the individual stationed at the north bank was clearly more vigilant in
recording planks, some vehicles were still missed, which were recorded on the south bank. Based on
careful matching of records from both sides of the crossing, a maximum estimate of 3110 m 3 planks was
established. However, this maximum estimate might be an overestimate due to data recording errors. For
example, if a particular vehicle is (accidentally) recorded in a differently manner on both sides of the
river, it may be treated as two different vehicles during analysis. For this reason, the estimate used in this
report is the average of the minimum and maximum estimates, or (2690 m 3 planks). Analysis and
crosschecking should therefore be conducted at the level of individual vehicles.
In conclusion, experience from this study showed that four main factors strongly contribute towards
greater data accuracy:
the strategic positioning of research assistants to detect as many vehicles as possible and help check
data accuracy (preferably situated where vehicles can stop and/or junctions of offroad logging
(panya) routes);
the careful selection of research assistants;
the use of two data gatherers per location to enable crosschecking; and
detailed analysis of records to the level of individual vehicles.
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