Method | Description | Determination of area |
---|---|---|
WHOPES |
Field surveyors count the number of holes in each of four categories: 1. Less than thumb-sized but greater than 0.5 cm (0.5 < diameter ≤ 2.0 cm) 2. Larger than a thumb but smaller than a fist (2.0 < diameter ≤ 10.0 cm), 3. Larger than a fist but smaller than a head (10.0 < diameter ≤ 25.0 cm) 4. Head-sized or larger (diameter > 25.0 cm) |
Each hole was assigned the midpoint area of the hole size category according to the guidelines: 1.2 cm^{2} 28.3 cm^{2} 240.5 cm^{2} 706.9 cm^{2} Note: no additional weighting was done |
Image analysis | ImageJ software processed digital images of each LLIN side to extract statistical data about shapes and edges, object counts, area, and location | Analyse particles tool yielded area measurements in cm^{2} (calibrated from square pixels representing the holes) |
Ruler | The length, width, and location (distance from the center of the hole to the bottom and side of the net noted as x and y coordinates) were measured using a tape measure (in mm) | The measured length and width were converted to area using the formula for the area of an ellipse calculated as A = π × a × b where a is ½ the length of the major axis and b is ½ the length of the minor axis |