I have been considering when are reference materials outdated? Our text (Toor and Weisburg 2007) suggests most reference materials older than 5 years are outdated. However when I reviewed the elementary school library geographical reference resources for assignment #2, I quickly noticed there were few materials which were younger than 5 years old. For assignment #2 I recommended the teacher-librarian use 10 years as the minimum copyright date. I also noted that local reference resources about my community are published infrequently and could be maintained for longer since they are revised on a much longer schedule.
I found it interesting that the change model we used for assignment #3 was developed in 1987, yet we could quote a much more recent reference for the model since it has been applied and discussed in literature from as recent as this year.
I realize the question doesn’t have an easy answer. It depends… should be how the question is answered.
It depends on the type of reference material. For example material on historical figures or history can be maintained for longer since the material doesn’t change. However the lens we use to filter the interpretation changes as society changes. This lens takes longer than 5 years to change so the material can be held for much longer. This is where I would place the assignment #3 model.
It depends on the length of time between revisions. For example materials that have a small market, such as local reference books are revised infrequently since it takes a long time to recoup the costs.
It depends on what happens in the world. For example, information about countries that have significant political changes (eg Hong Kong ) or wars will result in large changes in reference materials on that country. Also in this category are advancements in scientific knowledge. For example the "recent" change of Pluto to a dwarf planet and the acknowledgement of many more dwarf planets. Once the knowledge is printed in revised reference materials the TL has to determine how relevant it is to the school’s curriculum and how quickly this reference material should be replaced.
It depends on the material available in your library. I helped a librarian weed her non-fiction collection. When the librarian reviewed what I pulled she mentioned that some of the material she would retain since there was nothing else in her collection on the topic.
It depends on the professional skills of a Teacher-librarian to build and maintain a reference collection and the limitations of time and library budget. Skills I am improving by taking courses and collaborating with other teacher-librarians.
