The use of assessments should inform instruction and different assessments serve different purposes. The most effective use of reading assessments in the primary grades determines the why and then the how of instruction to meet the needs of students.
Screening tests provide information about the knowledge and skill base of the student.They are useful for determining the most appropriate starting point for instruction and for planning instructional groups. Screening tests usually include formal and informal measures with clear mastery targets. Testing systems such as AIMSweb(R), DIBELS(R), and easyCBM(R) provide assessments that are both screening tests and progress monitoring tools.
~Assessing Reading Multiple Measures, p.8
Progress monitoring is ongoing. Examples might include teacher observations, informal and formal tests, and curriculum tasks. Progress monitoring is used to determine whether students are making adequate progress, and also to determine whether instruction needs to be adjusted. Progress monitoring measures include curriculum-embedded assessments such as unit tests. Curriculum-based measurement (CBM) is an assessment tool that is often used for progress monitoring because it emphasizes repeated measurement over time. AIMSweb(R), DIBELS(R), and easyCBM(R) are some examples of ongoing progress monitoring systems. Ongoing progress monitoring may also include diagnostic tests that pinpoint the causes of a particular problem.
Progress monitoring serves to guide the specific focus of instruction. These tests are given at least three ties a year to all students. It is recommended that students who are beginning to fall behind their peers be assessed at least monthly, while students who have fallen considerably behind be assessed more frequently ---every two weeks or even weekly.
~Assessing Reading Multiple Measures, p.8, 9
Diagnostic assessments can also be used for screening or progress monitoring. These tests identify students' strengths and weaknesses in specific skills. Diagnostic tests should be given whenever a student is suspected of having difficulty learning what is taught.
~Assessing Reading Multiple Measures, p. 9
Outcome assessment is often used at the end of major units of instruction and at year's end. It provides data about exiting accomplishments and is useful for planning the next major segment of instruction and for determining changes to a school's curriculum. Outcome assessment usually leads to outcome evaluation, which represents a final judgment about a school's curriculum or about an individual student.
~Assessing Reading Multiple Measures, p. 9
If you are searching for some possible reading assessments (for screening, diagnostic, progress monitoring, or outcome), you may consider this chart found in Assessing Reading Multiple Measures which lists some possible assessments and times for use.