direction
[OED]: 9. a. The particular course or line pursued by any moving body, as defined by the part or region of space, point of the compass, or other fixed or known point, towards which it is directed; the relative point towards which one moves, turns the face, the mind, etc.; the line towards any point or region in its relation to other lines taken as known.
...most spatial coding situations require the use of two dimensions, rather than just one...adults remember both the distance of a point from the center of a circle (radial location) and the angular relation of the point to the radii of the circle (p 96). Distance and direction information with respect to either the self or to external landmarks, can be encoded at different levels of resolution and is known with varying degrees of certainty (p 27).
[Direction] . . .is an interval measure to the extent that its origin, usually (but not always) north is arbitrary, and it is meaningless to say that a line on a bearing of 090° is 'twice' 045° or 'half' 180°. There is also a problem in that the difference between 001° and 359° is not 358 but only 2° (p. 151/see source for more, much more).
Topic AM3-2. Define "direction" and its measurement in different angular measures; Compare and contrast how direction is determined and stated in raster and vector data; Describe operations that can be performed on qualitative representations of direction.
Direction and angle. To comprehend concepts of angle, orientation, and frame of reference (p. 95)
Develop language and means of expressing direction from a location (p. 698)
