Parents and caregivers usually receive and review several report cards throughout the school year.

They may also see the quizzes and read the papers that result in their kid’s average grades. But sometimes when standardized test reports go home, children’s scores don’t match the grades they’ve earned for their work in school. How can this be?

Grades and test scores do not always (or even often) agree; generally speaking, school grades usually reflect better performance and higher achievement than test scores.

For example, the Texas Education Agency administered the Texas Assessment of Knowledge and Skills (TAKS) to all public school students from grade three to eleven between 2003 and 2011. During that time, the organization conducted studies comparing the rates at which students passed their courses and passed the state tests. In 2009, the study showed that 88 percent of the 200,000-plus students in Algebra I passed the course, yet only 56 percent passed the 10th grade TAKS exam. Most of the other study results showed similar outcomes, with more students passing courses than standardized assessments.

Why the disparity?

First, and most importantly, grades and test scores measure different indicators of achievement. One factor that may contribute to the gap between them could be test anxiety, from which many students suffer during high-stakes assessments. But there’s more to it than nerves.

Let’s take a closer look at the specific differences between grades and scores.

Class-Based Grades

Students earn grades based upon their performance on a range of assessments, activities, and behaviors: quizzes, attendance, class participation, oral and written reports, group assignments, discipline, homework, and in-class work. Some districts align grades mainly with quantitative measures of performance. For example, the New York City Department of Education website explains that a student’s grade at the end of a marking period “represents an average of tests, quizzes, oral and/or written reports, homework, and class work as determined by school policy and the teacher.”

Other districts weigh different factors in student marks. The Seattle public school system, for instance, allows teachers to include measures like attendance, tardiness, and class participation when calculating student grades.

Grading policies can vary district by district, school by school, and even teacher by teacher. These rules are complicated even further by policies like minimum grade rules, extra credit, make-up work, homework, and good behavior. The combination of grading policies sometimes results in wide grade ranges, even within the same school.

Take minimum grade rules as an example. In Maryland, Montgomery County Public Schools enforce a policy that the minimum score for 6th-to-12th-grade assignments is 50, unless the student completes no work at all on a given assignment (in which case she gets a zero). Other districts, such as in Pittsburgh, Pennsylvania, have also instituted a minimum grade of 50 percent. Similarly, Shaker Heights Middle School in Ohio uses 45 as a minimum score for a missed assignment. Many school districts lack minimum grade policies, leaving individual educators to create their own rules, which, in turn, contributes to the variation among student results.

Another major difference between these two means of evaluation is that students can speak with teachers about grades to get a better sense of how and why they earned the marks they did. While they may receive some kind of explanation via a score report on a standardized assessment, these are usually not tailored to individual students.

Standardized Tests

In contrast to grades, standardized test scores are not assigned based on a very wide range of factors. Instead, they are designed to obtain a measure of student proficiency on a specified set of knowledge and skills within a few academic areas, such as mathematics or reading.

Because these tests are uniform, there are no policies or practices that vary across districts, schools, or teachers for the same exam. The scores from standardized tests reflect student performance under roughly the same conditions, so the results can be compared. It may go without saying, but this regularity is the biggest difference between class-based grading and standardized test scoring.

Most standardized exams are built to a test blueprint, which is a rubric-like tool that defines what a given assessment should measure and how it should measure it. Educators and administrators build blueprints before they create tests. These serve as specifications for exams, and set guidelines for how many sections and questions they should include, what types of questions they should pose (e.g., multiple choice, short answer, fill-in-the-blank, or essay), and the ways in which different questions will be used to measure different skills. Blueprints and standardized tests can be a tremendous source of data, which is difficult to gather through grades (where there is considerable variability).

Many states — like Indiana, Tennessee, and Missouri — offer blueprints covering multiple subjects (mostly for students in third grade and up) to families online at no cost. If you’re interested in checking these out, look online for your state’s department of education website and enter words like “assessment blueprint” into its search field.

How can we better align test scores and grades?

Since grades and test scores measure different things, parents can go through the school year thinking that their child is on track both to passing grades and acing assessments. However, as you might now guess, this isn’t a given.

One growing practice that may bridge the gap between grades and test scores is personalized learning, also known as competency-based learning. The U.S. Department of Education provides a resource for families seeking additional information on personalized learning, though it stops short of endorsing the practice.

In a competency-based learning environment, students’ performance is directly tied to their mastery of a particular set of skills as opposed to the various assessments and behaviors outlined above. Thus, competency-based grading only reflects the acquisition of certain knowledge and skills. Depending upon the alignment (or lack thereof) between material being taught and material being tested, personalized learning has the potential to change the relationship between test scores and grades.

To risk being reductive, critics of competency-based learning point out that the practice can be applied to standardized assessments, which is often called “teaching to the test” — in which curricula are geared toward high scores on evaluations. On the other hand, personalized learning can be applied to any number of constructive and worthwhile pursuits that most standardized exams don’t yet cover, like speaking a foreign language, building a useful website, designing a piece of energy-efficient technology, or writing a compelling piece of fiction.

Are there alternatives to grades and scores in general?

While competency-based learning and grading are becoming popular across the United States (and should help parents to understand grade and test information better), they’re still quite rare.

Even more of a departure from the norm are schools that choose to forgo grades altogether, opting instead for project-based learning, phenomenon-based learning, or experiential learning, all of which aim to prepare students for real-world challenges rather than for specific standardized exams.

For now, most parents can make better sense of the relationship between their child’s grades and test scores by figuring out exactly what each number — or letter — measures.

By asking questions about your school’s policies and the factors that make up each grade (extra credit, attendance, minimum grades for assignments, homework, make-up work), you can make better sense of report cards throughout the year. And by reviewing test blueprints, you may grasp more precisely what a test is meant to measure.

Putting these pieces together will give you a more holistic, and more accurate, picture both of your child’s achievement and of the areas in which she could use some extra help.