Access to desk-top structure and reaction databases through applications su
ch as Chemical Abstracts' SciFinder, MDL's Beilstein CrossFire, and ISIS Re
action Browser has led to changes in information seeking habits of research
chemists, the impact of which has implications when database purchasing de
cisions are made. A semiquantitative assessment is proposed which takes int
o account key aspects of structure and reaction databases. Assessment crite
ria are identified which can be weighted according to an organization's inf
ormation needs. Values are then assigned to criteria for each data source,
after which a formula is applied which leads to an indication of the relati
ve value of systems under consideration. The formula takes into account the
cost of database products and also the incremental benefit of adding a new
system to an existing collection. This work is presented as a generic appr
oach to the evaluation of databases and is not limited in scope to only str
ucture and reactions databases.