Comments on the corpus-based reference tools

Compare concordancers and collocation retrieval systems with dictionaries, each has their own advantages and disadvantages. The formers can't be a good choice for a new English learners for they only provide with lots of datas without further explainations or analysis, which may seem valuable for an advanced learner but not for a beginner. The numerous ill-organized datas may confuse the learners. On the other hand, dictionaries are more user-friendly and well-organized tools. I myself like all of the tools. Concordancers and collocation retrieval systems are such great tools for me to do research on the language changes in usage or on the collocation. Dictionaries, however, provide with more formal and specific explainnation on the usages I want to know.