にじゅうまる, まる, さんかく, ばつ【◎, ○, △, ×】
■ These four symbols are used to indicate comparative ratings, with ◎（にじゅうまる） being the best and ×（ばつ） the worst. ○（まる） is moderately good and △（さんかく） is moderately bad.
Sometimes only two symbols (○ and ×) or three symbols (usually ○, △, and ×) are used. × is also used by itself to mean "no good," "failure," etc.
The symbols may appear without explanation, as their meanings are generally understood, although sometimes, as in some of the examples below, each is assigned a specific meaning.
○ and × are used to mean "true" and "false" on tests. Such a test is called a ○×式（まるばつしき）のテスト.
□ The kanji corresponding to ◎ are 二重丸（にじゅうまる）, literally "double circle." ○ corresponds to 丸（まる）, "circle" and △ to 三角（さんかく）, "triangle." The word ばつ may be derived from the word 罰点（ばってん）, which is another name for the symbol ×.
(The above comes from a Web page listing the writer's ratings of various movies. ◎ means "recommended," ○ means "so-so," △ means "1,800 yen is too much" (1,800 yen being the price of a movie ticket), and × means "give me my money back." Web, August 2000.)
(The above is the key to ratings of a list of used book stores. The stores were rated according to the size of their stock of various categories of books. ◎ means "a wide selection," ○ "normal," △ "few books in this category," and × "almost none, or not carried at all by this store." Web, August 2000.)
(This example is from a self-rating quiz, where you are supposed to reply by clicking on the button that describes how well a particular statement replies to you. The scale runs from ×, which means "Does not apply to me very well" or "I don't think so" to ◎, which means "Applies quite well to me" or "That's exactly right." Web, August 2000.)
(The above table, found on the Web in August 2000, shows a typical use of these symbols. On the left are listed the names of various types of software, and across the top are features. Though it is not explained on the page, ◎ presumably means that the particular software implements that feature very well, ○ moderately well, △ barely adequately, and × poorly. The dash － means that the feature is not included at all or is not applicable.)