There's only one difficulty that teachers express with providing objects and pictures of objects to help children develop general information and word meanings for a topic under study. This difficulty relates to the vast investment of time teachers must spend in rounding up these objects and pictures. Vocabulary scavenger hunts are ways of gathering objects and pictures related to a topic under study in which the students, NOT the teacher do the hunting and gathering.
Cunningham, P., Crawley, S., & Mountain, L. (1983). Vocabulary Scavenger Hunts: A Scheme for Schema Development. Reading Horizons, 24 (1). Retrieved from http://scholarworks.wmich.edu/reading_horizons/vol24/iss1/8