One common problem in geography is the need to portray data that have been collected to show spatial variability. The medium most commonly used is that of a map. A very effective type of map is one which uses isolines a line that joins points of equal value.
This allows the researcher to assess the prevalence of a disease or of other variables of interest.
The methods can be standardized by the researcher, and clear-cut definitions can be applied to the exposure and the endpoints. This enables the researcher to categorize subjects with regard to previous exposure even if the information is collected at a set point in time.
To a large extent the interpretation of cross-sectional studies is similar to that of case-control studies. The lack of the dimension of time implies that cross-sectional studies are poorly suited to the examination of diseases of shorter duration.
In a cross-sectional study in Norway, those who were most overweight in the population were also those who reported consumption of low-fat milk. Although it is unreasonable to infer that low-fat milk increases body weight, the finding does reflect attempts to lose weight.
As in this example, the findings of cross-sectional studies should be interpreted carefully. An increasing problem in cross-sectional and cohort studies is the low response rate or attendance rate, an issue that may invalidate the results of the studies with regard to prevalence assessment.Sep 03, · A step by step explanation on how to draw a cross section.
You would use a topographic map with contour lines for this.
Don't forget to watch my other Geogra. In this method cross-sectional points are taken at regular interval. By levelling the reduced level of all those points are established. The points are marked on the drawing sheets, their reduced levels (RL) are marked and contour lines interpolated.
A cross-sectional study to compare intraocular pressure measurement by sequential use of Goldman applanation tonometry, dynamic contour tonometry, ocular response analyzer, and Corvis ST. A cross-section is a slice through a particular feature. 1 Decide where you want the cross-section line to be.
To draw the shape of a river valley, the line is the frame and mark on a dot for each contour line in the correct place.
The distance along the bottom should be the same as on the scrap paper. In this method cross-sectional points are taken at regular interval.
By levelling the reduced level of all those points are established. The points are marked on the drawing sheets, their reduced levels (RL) are marked and contour lines interpolated. Cross Sectional Study. Cross-sectional studies are a type of descriptive epidemiologic study in which the exposure and disease status of the population are determined at a given point.
In a cross-sectional study in Analysis of such studies should always report the number of eligible individuals who were initially selected and approached.