What is the rhyme and meter of "Miniver Cheevy" by Edwin Arlington Robinson? What effect does this structure give to the impact of the poem?

The rhyme scheme of the poem is abab in each stanza. This is a typical rhyming pattern for ballads; however, many of the end rhymes are feminine rhymes, which is not necessarily typical of ballads. The rhythm is mainly iambic, with an unstressed syllable followed by a stressed syllable, which is a typical ballad rhythm. However, this rhythm is broken up by the name "Miniver," which has a dactylic rhythm (one stressed syllable followed by two unstressed syllables). Besides that variation, the use of feminine rhymes at the end the second and fourth lines of each stanza causes the rhythm to break from strict iambic as well. Feminine rhymes are rhymes that take two or more syllables, such as "prancing" and "dancing." Since these rhymes end on an unaccented syllable, the lines containing these rhymes have an extra syllable in them, throwing off the iambic rhythm. Having an extra syllable that is not part of a rhythmic foot is called hypercatalexis. The line length, or meter, in "Miniver Cheevy" varies from the typical ballad meter. Typically ballads have four-line stanzas that have four feet in each line (eight syllables), or each stanza's lines alternate between having eight syllables and six syllables. In this poem, the first three lines are modified four-foot lines, but the final line of each stanza is a two-foot line with hypercatalexis. 

The variations of rhythm, meter, and rhyme from the standard ballad format make this poem feel off-kilter. A steady iambic rhythm gives a poem a smooth, lilting feel. However, in this poem, each stanza starts with a "Miniver," a dactylic foot that sets the stanza off on the wrong foot, so to speak. The extra syllable thrown in at the end of the second line is another surprise as the foot stops in mid-air. Finally, the last line of each stanza, cut short and containing an extra syllable, makes each stanza feel like it is full of fits and starts. All these variations work together to give the poem a staggering feel, much like a drunken man--in fact, much like Miniver Cheevy.