When searching by Chinese you can tell the dictionary to find entries that start with the characters, end with the characters, or have the characters anywhere within the final word. You can also ask to only return the Chinese entries that exactly match the word being sought.
When searching by pinyin, you must include a space between the different pinyin syllables. You can include or exclude tone numbers (1-4 and 5 for the neutral tone). For example, if you were looking for the word for television set, you would type "dian shi ji" or "dian4 shi4 ji1" or "dian shi4 ji" (but without the quotes). All would work. But remember to include the space and set the dictionary to look for pinyin, and not Chinese characters or English. As with the Chinese characters, you can direct the dictionary to find entries that have the pinyin at the beginning, end, anywhere, or as the whole entry. You can return the results in GB, Big5 or UTF-8 Unicode.
When searching by English, searches are not case sensitive. Since this is designed as mainly an Chinese to English and not English to Chinese dictionary, if you can't find the word you are looking for, you may be able to find it using a synonym. Also, you may get many unrelated entries that use the word in the English definition but do not give the equivalent Chinese for it.