WORD		GRADE TESTED*	% KNOWN*	MEANING KNOWN*	SUGGESTED CONTEXT
antidote		10	71	against poison	biology, epidemiology (plants, snakes, diseases)
capacity		08; 10	77%	ability; position served in	any science or math context
	molt			shed feathers, skin, hair, shell, antlers, etc. before new growth.	zoology (lobsters, birds, snakes ?)
	metamorphosis	10	72%	change of form	biology (caterpillars, moths, butterflies)
	creature	6	67%	a living thing	zoology
	avalanche			a large mass of snow and ice loosened from a mountainside	ski or snowboarding magazines/websites, science texts
	obsolete	10	71%	out of date	any SMET context
species		6	67%	subgroup of	biology, zoology
	poach; poachers	12	72%	take game or fish without any right	hunting, ecology, endangered species
	stagnant	10	73%	not fresh	biology, marine biology, articles about ponds, rivers, etc.
	dehydration	8	78%	removing water from	health, sports
	emerge			come into view; come out, come up	biology or any science context
	variable	08	83%	changeable

	WORD	GRADE TESTED*	% KNOWN*	MEANING KNOWN*	SUGGESTED CONTEXT
comet		8	79%	heavenly body	astronomy, earth science
forthcoming		8	80%	approaching	any SMET context

Word meanings derived from:

*Dale, E. & O'Rourke, J.O. (1976). The living word vocabulary: The words we know - a national vocabulary inventory. Elgin, IL: Field Enterprises Educational Corporation.

Dale and O'Rourke measured word meaning knowledge through multiple choice word meaning tests. They tested target words at various grade levels: grades 4, 6, 8, 10, 12, 13, and 16. During the trials, if a word received a score of 66% or higher, that word was retested at the next level. According to Dale and O'Rourke, a final score between 67-84% is desirable if a word is to be used in a text to be read independently by that level of student. Scores less than 50% mean that the word is a hard word. Scores less than 33% mean that the majority of students at that grade has no knowledge of the word.

The words chosen are arbitrary; they were selected randomly by scanning available words with upper school students in mind. A science context was assumed for most words.