Symbolisation and Visual Variables Questions and Answers

Answer: C

Contours are the familiar case, joining points of equal height, but the same construction serves temperature, pressure and rainfall. Restricting the idea to elevation alone is a common but avoidable narrowing of the term.

Answer: D

The first and third are correct, since a rate suits area shading and a point symbol escapes the unit-size problem. The second is wrong: dots are placed to convey the distribution within a unit and are not individually surveyed positions.

Answer: A

A selective variable lets the eye isolate a group without inspecting each symbol, which is what colour hue does well. Ranking is a separate property, called ordered, and estimating amounts is the quantitative property.

Answer: B

Correct answer: Size

In Bertin’s scheme size is the only one of these that is quantitative: the eye can judge that one symbol is about three times another, so ratios can be read from it. Value and density are ordered but not quantitative - a darker tone reads as more, not as twice as much - while hue, shape and orientation are merely associative or selective and carry no order at all.

Answer: C

A cross for a church and a crossed pick for a mine differ in kind, not in amount, and shape carries that distinction without implying either order or magnitude. Its weakness is that small shapes become hard to tell apart.

Answer: D

The reverse is closer to the truth. Orientation is read easily in a line or a hatching pattern, while a small point symbol offers too little to show a clear angle, and rotating it often makes it look like a different shape altogether.

Answer: A

A pattern needs room before its spacing becomes legible, so small units fill with what looks like a single tone. It reproduces perfectly well in black and white, which is why it survives on maps that cannot use colour.

Answer: B

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason is the cause. Photocopying discards hue and keeps only lightness, so a red and a green of similar value collapse to the same grey and the categories become indistinguishable. Texture, pattern and hatching survive the reduction because they differ in structure rather than in colour - and the same reasoning underlies designing for colour vision deficiency.

Answer: C

Correct answer: 8 mm

Area is scaled with the value, and area goes with the square of the radius, so the radius goes with the square root of the value: \[ r = 4\sqrt{\frac{400}{100}} = 4\sqrt{4} = 8\ \mathrm{mm}. \] Scaling the radius directly by the fourfold increase gives the 16 mm offered, which would make the circle sixteen times the area rather than four - the classic exaggeration in proportional symbol work.

Answer: D

Dividing 12,000 by the dot value of 500 gives 24 dots. Choosing that value is a design decision: too large and sparse areas show nothing, too small and dense areas coalesce into solid black. Dot size and dot value are therefore chosen together.