Recall that "continuous revision" requires a list of collection subjects and a schedule for the evaluation of each one. There should be an emphasis on more frequent evaluation of those subjects where obsolescence is a problem.
Perfection can be the enemy of collection development and management (CDM). Too many information professionals wait for that "big block of time" in order to do it right. Lacking that time, they hesitate and the project is never done. G.K. Chesterton is quoted as saying that "if it's worth doing, it's worth doing poorly." He was NOT suggesting that you intentionally do a poor job. Rather, he meant that one should go ahead and do it, learn from the experience, and do it better next time.
In order to develop a collection, you must be able to describe its scope. Often, there are differences of opinion in regard to what a subject includes or should include. Working with those most likely to use the collection, you need to develop a list of the major elements or components or aspects of the collection that you intend to develop. The more specific that you can be about scope, the better the resulting collection. It is also useful to identify and list related subjects (to be developed or evaluated at another time).
Libraries often limit scope through the use of appropriate subject headings and class numbers. Some special libraries will use subject descriptors taken from an appropriate thesaurus or subject-focused abstracting service. However you do it, the key is your ability to tell a prospective user exactly what topics will be included. Sometimes, this can be difficult. For example, the literature and contact with users suggest that there are many definitions of what should be included in the "Science Fiction" collection.
When the subject scope is delimited or defined, the collection developer considers the rationale or justification for developing this collection. Since justification may depend on the nature of the collection, it could be done after or before the definition. Several variables are normally considered and are mentioned below. You may wish to add others to meet your particular situation.
Some subjects appear to be more valuable than others. While this may seem to be entirely subjective, it remains worth-while. The notion here is that the subject must contribute to the quality of life in the community and that some subjects do more of that. Quality of life may be variously defined, and might include increased productivity, the ability to make or do things, and increased mental health resulting from "escape" and exposure to beauty.
Popularity is easier to measure than value, but may still be a problem. Here, we would hope to add items to a collection where interest has been expressed and collection use is likely in the future. We also look for events in the community likely to stimulate interest in a particular collection. Events may range from a course presentation to a plant closure or a new research and development initiative. Repeated events are especially noteworthy. Finally, we attempt to anticipate the "life of the demand" or interest. We are most likely to develop a collection when demand is likely to be long and steady.
Ideally, we would develop unique collections to stretch our scarce resources. There may be no need to develop a collection if a similar collection is readily available for our audience. For example, a college library may not provide recreational reading when a public library in the community does that. We begin by identifying other sources or providers in the community which are accessible for our audience. Once identified, we attempt to summarize their attributes,especially cost of use and physical accessibility (includes hours of service). We then come to a conclusion on the degree to which these alternatives lessen the need for a locally developed collection.
We are more likely to develop a collection when appropriate, current, and relatively inexpensive material is available. We are less likely to develop a collection when few items are available and they are expensive and dated. Using standard sources, for example Books in Print, we attempt to characterize the likely pool of available items. Currency is most important for some subjects and less important for others. In developing scientific, technical, and medical collections, a pool of current items is important. In developing collections in the humanities, a pool of older items may be just fine. Here we consider the harm or risk involved in selecting older items.
Based upon the responses to the questions raised above, we then decide whether or not to develop the collection and which aspects to emphasize.
Select an information provider of your choice. Create a list of subjects where obsolescence is likely to be a problem. Create a list of subjects where obsolescence is not likely to be a problem. Be prepared to provide a rationale for your selections.
Select an information provider of your choice. Create a list of information providers or sources that your audience may use instead of a local collection developed by you. Be able to discuss the assets and liabilities associated with these competitors.
Select an information provider of your choice. Create a list of subjects likely to have high value for quality of life in the community. Prepare a rationale for your selections.