The recent techniques for query expansion in Thai retrieval
system are based on predefined word relationship. We have
investigated a new approach to recover query ambiguousness
problem in Thai library automation system. Our technique employs
genetic algorithm and information on MARC-21 format
which is data format in our library automation system, Walai
autolib. The experimental results indicate that our participants
have 65% in average agreed that our query expansion is able to
assist users searching their materials. High educational users
which are lecturer and postgraduate students quite agree that
our expanded queries are useful. In the future work, we plan
to investigate on parameter tuning for genetic algorithm which
is most suitable for Thai language system. The influences of
crossover and mutation on generating topic diversity should
be more analysed.