Methods for constructing and maintaining knowledge representation systems (KRS) are disclosed. The KRS is initially organized and populated using knowledge engineers. After initial organization, scientific domain experts digest and structure source texts for direct entry into the KRS using templates. These templates constrain both the form and content of the digested information, allowing it to be entered directly into the KRS. The methods disclosed herein permit the construction and maintenance of a much larger KRS than could be constructed and maintained using known methods. Fact type specific fact templates are completed, accepting predefined fact types found in predetermined information sources. Fact template may comprise a user interface that constrains user entry to one of a predetermined set of valid entries. The user interface may include a user field that permits entry of new information not included in the predetermined set of valid user entries.