Open AccessOn vital aid: the why, what and how of validation
Author(s) -
Kleywegt Gerard J.
Publication year - 2009
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s090744490900081x
Subject(s) - computer science , process (computing) , experimental data , data mining , a priori and a posteriori , statistics , mathematics , philosophy , epistemology , operating system
Limitations to the data and subjectivity in the structure‐determination process may cause errors in macromolecular crystal structures. Appropriate validation techniques may be used to reveal problems in structures, ideally before they are analysed, published or deposited. Additionally, such techniques may be used a posteriori to assess the (relative) merits of a model by potential users. Weak validation methods and statistics assess how well a model reproduces the information that was used in its construction ( i.e. experimental data and prior knowledge). Strong methods and statistics, on the other hand, test how well a model predicts data or information that were not used in the structure‐determination process. These may be data that were excluded from the process on purpose, general knowledge about macromolecular structure, information about the biological role and biochemical activity of the molecule under study or its mutants or complexes and predictions that are based on the model and that can be tested experimentally.