Words can be classified by type according to their relative difficulty to decode. Typically this continuum is listed from easy to difficult, beginning with VC and CVC words that begin with continuous sounds and progressing to CCCVC and CCCVCC words. Coordinated instructional sequences take into consideration how information is selected, sequenced, organized, and practiced. Coordinated instructional sequences occur within each component of reading where a logical progression of skills would be evident easier skills are introduced before more difficult skills, so that skills build progressively. The other way coordinated instructional sequences are evident is in the clear and meaningful relationship or linking of instruction across the five components of reading: phonological awareness, phonics, fluency, vocabulary, comprehension. If students orally segment and blend words with the letter-sound /f/ during phonemic awareness instruction, then we would expect to see it followed by practice in connecting the sound /f/ with the letter f. This would be followed by fluency practice in reading words, sentences, and/or passages with the letter-sound /f/. Spelling practice would include /f/ and other previously learned letter-sounds. Core Instruction is instruction provided to all students in the class, and it is usually guided by a comprehensive core reading program. Part of the core instruction is usually provided to the class as a whole, and part is provided during the small group, differentiated instruction period. Although instruction is differentiated by student need during the small group period, materials and lesson procedures from the core program can frequently be used to provide reteaching, or additional teaching to students according to their needs.