Teachers must be systematic in developing an appropriate sequence of activities and in choosing examples of words and sound units for strengthening students´ phonological awareness. Four dimensions of words that contribute to phonological difficulty are the size of the sound unit, the number of sound units, the position of the sound units/cluster within the word, and the phonological properties.

Although the goal is to work with the smallest sound units --phonemes-- to help students begin to understand how to start thinking about the sounds in words, it may be necessary to start with larger sound units. Prior to blending and segmenting words at the phoneme level, students may need to work with larger sound units, such as compound words, two- and three-syllable words, and onset-rime units in one syllable words.The number of sound units is also a consideration. It is easier to work with words with two or three sound units than to work with words that have four or more sound units. The number of letters in a word does not necessarily relate to the number of sound units in a word.

Another consideration when asking students to detect or identify sound units is the position of the sound unit. Sound units at the beginning of words are the easiest to detect. The next easiest to detect are sound units at the end of words. Sound units in the middle of words are the most difficult to detect or identify. This applies to both the syllable and phoneme levels.

The phonological properties or the characteristics of the phonemes also contribute to the difficulty of a word. For instance, words with continuous sounds, single consonants, and voiced phonemes are easier for students to compare, blend, and segment than are words with stop sounds, consonant blends or clusters, and unvoiced phonemes.

In summary, to increase the opportunities for students to be successful, it is important that each of these dimensions be considered in relation to the students´ prior knowledge when choosing examples of words to use to strengthen students´ phonological awareness.