D187 Assessment
A music teacher is creating a proficiency scale for students for the measurement topic of song composition. Which proficiency scale statement measures procedural knowledge at advanced level 4.0 proficiency for the given measurement topic? The student will identify the parts of a song. The student will compose and sing a song, including two verses and a chorus. The student will compare the choruses and verses of several songs. The student will distinguish between different types of songs.
The student will compose and sing a song, including two verses and a chorus.
How are measurement topics beneficial to teachers? They enable teachers to assess all the required state standards. They help teachers identify a small set of themes to focus on during instruction. They enable teachers to rename groups of focus statements. They help teachers avoid incidental learning that is unrelated to the measurement topic.
They help teachers identify a small set of themes to focus on during instruction.
How do proficiency scales help teachers create assessments? They provide detailed descriptions of the specific knowledge and skills that are considered most important for each grade band. They provide a continuum of knowledge levels and skills related to a specified standard. They list statements of approved educational benchmarks at specified grade levels. They provide a collection of learning targets with complexity beyond an academic standard.
They provide a continuum of knowledge levels and skills related to a specified standard.
What is the purpose of parallel assessments? To determine a student's report card grade To determine student placement in advanced classes To determine whether a student should pass or fail a course To determine a student's depth of knowledge of a measurement topic
To determine a student's depth of knowledge of a measurement topic
Why are mathematical models used in standards-based grading? To estimate student true summative scores To estimate student true formative scores To measure student true summative scores To measure student true formative scores
To estimate student true summative scores
What is the purpose of parallel assessments? To compare two students who have the same proficiency level To assess students using items with varying levels of difficulty To measure multiple learning standards simultaneously To track student progress on singular learning objectives
To track student progress on singular learning objectives
What is important to consider about the accuracy of true scores when assessing student knowledge? True scores are not accurate measurements of student knowledge because every assessment contains some inherent error. True scores are not accurate measurements of student knowledge, so efforts would be better spent making error-free assessments. True scores are accurate measures of student knowledge because every assessment inherently contains some error that must be accepted. True scores are accurate measures of student knowledge, but efforts should be made to reduce assessment errors.
True scores are accurate measures of student knowledge, but efforts should be made to reduce assessment errors.
What characteristic of parallel assessments refers to the measuring of the same trait on all forms of the test? Unidimensionality Internal consistency Vertical scalability Fairness
Unidimensionality
Which focus statement represents procedural knowledge? Comprehends prime factorization Knows the Pythagorean theorem Remembers the quadratic equation Writes Roman numerals from 1 to 100
Writes Roman numerals from 1 to 100
"Determine a theme or central idea of a text and analyze in detail its development over the course of the text, including how it emerges and is shaped and refined by specific details; provide an objective summary of the text" .Proficiency LevelLearning Target 4.0The student will analyze the development of a theme in a given text and argue for the strengths and weaknesses of the author's choices. 3.0The student will explain the theme or main idea of a given text, provide a summary, and show how the author uses literary or rhetorical devices to develop it. 2.0The student will determine the theme or main idea of a given text and provide a summary. 1.0The student will identify the main events or ideas in a text. Which proficiency scale level corresponds with an assessment item that asks students to drag and drop options to organize the events in a text chronologically? 1.0 2.0 3.0 4.0
2.0
A student achieved the following assessment scores for a measurement topic, based on a four-point proficiency scale: 2.0 2.0 2.5 3.0 4.0 What is the student's summative score, rounded to the nearest tenth, using the average model? 2.7 2.9 3.0 3.3
2.7
A 10th-grade world history teacher is reviewing the following standard for the curriculum and making note of the measurement topics: HSS-10.2.2: "List the principles of the Magna Carta, the English Bill of Rights (1689), the American Declaration of Independence (1776), the French Declaration of the Rights of Man and the Citizen (1789), and the U.S. Bill of Rights (1791)" (California Department of Education, 1998). Which measurement topic aligns to the given standard? Historical documents Modern warfare Human migration U.S. Constitution
Historical documents
A fourth-grade social studies teacher is reviewing the following standard for the curriculum and making note of the measurement topics: SOCIAL STUDIES.4.5.A: "Explain the impact of various events on life in Texas such as the Great Depression, the Dust Bowl, and World War II" (Texas Essential Knowledge and Skills for Social Studies, 2018). Which measurement topic aligns to the given standard? Politics Geography History Government
History
Reliability
If the assessment has good reliability, the student's assessment score will accurately identify the level of learning and drive instructional planning for achieving greater levels of mastery.
A teacher is developing an assessment blueprint that includes a standard four-point proficiency scale.How should the teacher allocate the number of items for each proficiency level? Include an equal number of items for each level Include a decreasing number of items for each level as complexity increases Include more items that assess levels 2.0 and 3.0 than other levels Include an increasing number of items for each level as complexity increases
Include a decreasing number of items for each level as complexity increases
What is a benefit of a standards-based grading system for high-achieving students? Instruction can be easily adjusted to provide new, more complex learning targets. It is easy to keep high-achieving students motivated with high scores on most assignments. High-achieving students can be identified easily by comparing student scores. It is easy to create special assignments and extra credit opportunities for high-achieving students.
Instruction can be easily adjusted to provide new, more complex learning targets.
A high school digital media teacher has completed the assessment blueprint for the given measurement topic and standard and is now writing the assessment. The teacher is considering the following assessment item for the target 3.0 proficiency level: "Compare and contrast the development of similar themes across two or more media products and analyze how they emerge and are shaped and refined by specific details" (Indiana Department of Education, 2023).Item for Consideration: Generate a research project that compares, contrasts, and analyzes the theme of school choice across at least three forms of digital media. What is problematic about including this item? It assesses content that is unrelated to the standard. It contains biased content. It is not constructed properly. It does not assess the correct proficiency level.
It does not assess the correct proficiency level.
What is true about determining the best-fit model? It is determined by comparing error rates between the true scores predicted and the actual scores observed. It is determined with the assumption that learning remains the same from one assessment to the next with equal average scores. It is determined with the assumption that a student's learning occurs in steady and equal increments to produce true scores. It is determined by estimating the student's current summative score based on observed scores.
It is determined by comparing error rates between the true scores predicted and the actual scores observed.
Point scoring
It is used to determine the percentage of available points a student earned on sections of a test, which is translated into a score on a proficiency scale.
Which component of an assessment blueprint increases complexity? Proficiency scales Item types Performance indicators Backmapping process
Item types
A teacher must determine a relevant focus statement based on this standard for a U.S. history course: "The student understands the differences between the economic, technological, and human resources of both sides of a conflict." Which focus statement reflects this standard? Debates the pros and cons of an economic relief policy Explains the timeline and outcome of a national conflict Knows about the materials that contributed to an event and its outcome Uses primary sources to describe the events leading up to a conflict
Knows about the materials that contributed to an event and its outcome
A student achieved the following assessment scores for a measurement topic, based on a four-point proficiency scale: 0.5 1.5 2.0 2.0 2.5 2.5 3.0 The teacher estimated the student's true summative score, rounded to the nearest tenth, is 3.1. Which mathematical model did the teacher use to estimate the student's true summative score? Average Median Linear trend Decaying average
Linear trend
Parallel assessment
Multiple assessments assessing the same topic at the same difficulty level—can help measure student progress toward mastery of a standard.
Which components of an assessment blueprint ensure proper assessment coverage? Number and types of test items Measurement topics and standards alignment Item difficulty and rubric descriptors Percentage of items and difficulty level for each topic
Percentage of items and difficulty level for each topic
Which factor distinguishes norm-referenced grading from standards-based grading? Grade point average (GPA) Performance of the rest of the class Definition of grading standards State accountability standards
Performance of the rest of the class
A 10th-grade English language arts (ELA) teacher is reviewing the following standard for the curriculum and making note of the measurement topics: CCSS.ELA-LITERACY.W.9-10.1: "Write arguments to support claims in an analysis of substantive topics or texts, using valid reasoning and relevant and sufficient evidence" (Common Core Standards Initiative, 2021). Which measurement topic aligns to the given standard? Vocabulary Persuasion Transitions Audience
Persuasion
An eighth-grade social studies teacher is reviewing the following standard for the curriculum and making note of the measurement topics: INQ 9-12.5: "Determine the kinds of sources that will be helpful in answering compelling and supporting questions, taking into consideration multiple points of view represented in the sources, the types of sources available, and the potential uses of the sources" (Connecticut Social Studies Frameworks, 2015). Which measurement topic aligns to the given standard? Debate Thesis statements Historical context Research
Research
Screener
Screening is a type of assessment that helps teachers identify students who are not meeting grade level learning goals. Screening assessments check for warning signs to see if students might be at risk for reading difficulties, including dyslexia.
A high school theater arts teacher is reviewing the following standard for the curriculum and making note of the measurement topics: B.AE.1.2: "Explain how the major technical elements, such as sound, lights, set, and costumes, are used to enhance formal or informal productions" (North Carolina Essential Standards Theatre, 2019). Which measurement topic aligns to the given standard? Nonverbal communication Stage design Stage blocking Vocal expression
Stage design
A grading scale reflects the following details: 4 achievement levels — Advanced 3 achievement levels — Meets expectations 2 achievement levels — Partial mastery1 achievement level — Little or no mastery Which grading system does this grading scale represent? Norm-referenced grading Standards-based grading Criterion-referenced grading Percentage-based grading
Standards-based grading
What is a benefit of using standards-based grading compared to norm-referenced grading? Standards-based grading provides more feedback than norm-referenced grading. Standards-based grading is more open to adjustments in instruction than norm-referenced grading. Standards-based grading is easier for score users to understand than norm-referenced grading. Standards-based grading is more focused on the learning targets than norm-referenced grading.
Standards-based grading is more focused on the learning targets than norm-referenced grading.
An English language arts teacher is unpacking the following standard: CCSS.ELA-Literacy.RL.7.10: "By the end of the year, read and comprehend literature, including stories, dramas, and poems for grades 6-8 text complexity band proficiently with scaffolding as needed, at the high end of the range" (Common Core Standards Initiative, 2021). Which terms reflect the content of the standard? Read, comprehend Stories, dramas, poems Complexity, scaffolding Year end, high end of the range
Stories, dramas, poems
Which measurement topic aligns to the following standard? "Support claim(s) with logical reasoning and relevant evidence, using accurate, credible sources and demonstrating an understanding of the topic or text" (National Governors Association Center for Best Practices & Council of Chief State School Officers, 2010). Prior knowledge Components of an essay Supporting evidence Nonfiction texts
Supporting evidence
Which problematic assessment practice does standards-based grading help teachers avoid? Sampling one individual standard rather than multiple standards Merging state and district standards Unpacking sets of standards Tagging multiple standards
Tagging multiple standards
Why do teachers only grade student work related to the achievement of learning targets in standards-based grading systems? Behaviors like participation and attendance are too subjective to grade. Behaviors like participation and attendance are not as important as learning targets. Teachers are able to help students focus on learning goals and track their progress. Teachers are able to assign more assessments and provide more frequent feedback.
Teachers are able to help students focus on learning goals and track their progress.
What indicates the concept of best fit when analyzing assessment scores? The lowest percentage of error between actual and predicted scores The highest percentage of error between actual and predicted scores The least difference between actual and predicted scores The greatest difference between actual and predicted scores
The lowest percentage of error between actual and predicted scores
Mounting Evidence
The method of mounting evidence involves considering the most recent evidence or data as the most relevant in determining a student's progress or performance.
Which score must be considered when using the method of mounting evidence to determine a student's summative score? The most recent assessment score The oldest assessment score The average score of all assessments The most frequent score on all assessments
The most frequent score on all assessments
How is a narrative-based system different than a standards-based grading system? The narrative grading system uses proficiency scores to a great extent, but the standards-based grading system does not. The standards-based grading system uses proficiency scores, but the narrative grading system does not. The narrative grading system is used to determine proficiency scores for written tasks, while the standards-based system is used for other performance tasks. The standards-based system is used to report state-level proficiency scores, while the narrative grading system is used for informal evaluations.
The standards-based grading system uses proficiency scores, but the narrative grading system does not.
A student achieved the following assessment scores for a measurement topic, based on a four-point proficiency scale: 1.0 1.0 1.5 1.5 1.5 2.0 2.0 2.0 Which conclusion can be drawn about the student's mastery of the content? The student is demonstrating exceeding proficiency. The student is demonstrating target proficiency. The student is demonstrating emerging stages of proficiency. The student is demonstrating a need for support to demonstrate proficiency.
The student is demonstrating a need for support to demonstrate proficiency.
A student achieved the following assessment scores for a measurement topic, based on a four-point proficiency scale: 1.5 2.5 2.5 3.0 3.0 3.0 3.5 3.5 Which conclusion can be drawn about the student's mastery of the content? The student is demonstrating exceeding proficiency. The student is demonstrating proficiency. The student is demonstrating emerging stages of proficiency. The student is demonstrating a need for support to achieve proficiency.
The student is demonstrating proficiency.
A teacher wants to design a proficiency scale that will consider each student's varied level of understanding of the measurement topics. Which type of proficiency scale offers this benefit? Demonstration-of-skills scale Consistency-of-behavior scale Half-point scale Generic scale
Half-point scale
Which example illustrates response-code scoring? High partial accuracy (HP) Section B score: 5/40 = 13% Overall score obtained: 35/40 Advanced proficiency level
High partial accuracy (HP)
A teacher wants to design assessments that assess individual students at their specific proficiency level.What should be included in the assessment blueprint to ensure the proper complexity levels are assessed for each student? A scoring rubric Descriptions of relevant task models A screener Questions equated to comparable difficulty
A screener
"Evaluate claims, evidence, and reasoning that the complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem" 4.0The student will make predictions about changes to ecosystems. 3.0The student will classify creatures that dwell in different ecosystems based on a predator status. 2.0The student will describe elements of various ecosystems.1.0The student will identify different ecosystems. Which could the teacher include to assess advanced level 4.0 proficiency? Drag-and-drop items that ask students to match animals to the ecosystems they live in Multiple-choice items that ask students to select the correct ecosystem Matching items that ask students to identify different ecosystems A short essay that asks students to elaborate on the potential impact climate change might have on a specific ecosystem
A short essay that asks students to elaborate on the potential impact climate change might have on a specific ecosystem
Write wellorganized and cohesive arguments, distinguishing claim from opposing claims and use language to clarify connections among claims, reasons, and evidence 4.0The student will analyze the distinction between opposing claims and apply clarifying language based on reasons and evidence 3.0The student will craft structured and cohesive arguments using appropriate language, making connections with reasons and evidence 2.0The student will distinguish the difference between claims, reasons, and evidence in a well-organized argument 1.0The student will identify a topic for an argument to present in a composition Which can be included to assess target level 3.0 Singleselect multiplechoice items that ask students to identify thesis statements Multipleselect multiplechoice items that ask students to classify claims An extended constructedresponse item that asks students to offer and support an opinion A research project
An extended constructed-response item that asks students to offer and support an opinion
Describe the relationship between a series of historical events, scientific ideas or concepts, or steps in technical procedures in a text, using language that pertains to time, sequence, & cause/effect 4.0The student will evaluate the steps involved in a scientific procedure & critique the cause and effect of the steps 3.0The student will organize scientific concepts & analyze the relationships using key details 2.0The student will interpret the sequence & relationship of a series of steps in a scientific process 1.0The student will identify the steps in a scientific process Which assessment item corresponds to 3.0 Apply key details to classify given scientific topics & examine the relationships Generate guidelines to complete a scientific procedure, including the cause&effect relationship Recognize and list key steps in a scientific process Summarize the reasons for completing each step in a scientific process
Apply key details to classify given scientific topics and examine the relationships.
Use geographic tools, resources to analyze Earth's human systems,physical features to investigate, address geographic issues 4.0The student will construct a visual representation of a specific Earth system & its features and will assess the environmental impact 3.0The student will analyze a specific Earth system & its features and will explain the environmental characteristics 2.0The student will classify the physical features of a specific Earth system 1.0The student will recognize physical features of a specific Earth system Which item corresponds to 2.0 Match the physical features with the correct Earth systems Analyze one Earth system & its physical characteristics Arrange the physical features of the given Earth systems according to their correct categories as living or nonliving Create a multimedia slideshow of an Earth system & label physical features with notations assessing the environmental impact
Arrange the physical features of the given Earth systems according to their correct categories as living or nonliving.
Which statement is a criticism of standards-based grading systems? Assessments are too narrowly focused. There is little room for differentiation. Instruction is too rigid. The system requires teachers to be experts in state standards.
Assessments are too narrowly focused.
How do standards-based grading systems support struggling students compared to other common grading systems? By giving fewer summative assessments By focusing on positive feedback rather than negative feedback By allowing students to redo lessons and assignments as many times as necessary By providing many easy-to-master assignments
By allowing students to redo lessons and assignments as many times as necessary
How do proficiency scales address weaknesses in standardized performance assessments? By providing specific feedback to students By evaluating each assessment with a numeric score By predicting specific learning patterns for students By encouraging increased instructional time for core subjects
By providing specific feedback to students
Which focus statement represents procedural knowledge? Learns how to use a calculator Composes sentences using a keyboard Memorizes spelling words Recalls the associative property of multiplication
Composes sentences using a keyboard
Which focus statement represents declarative knowledge? Comprehends who the antagonist is in a short story Explains who the audience is in a persuasive essay Predicts who the protagonist is in a novel Supports with evidence the theme of a biography
Comprehends who the antagonist is in a short story
What is one difference between using criterion-referenced scoring in standards-based grading systems as opposed to using norm-referenced scoring? Criterion-referenced scoring is easier to use when determining class rank than norm-referenced scoring. Criterion-referenced scoring is not used on standardized tests, while norm-referenced scoring is. Criterion-referenced scoring uses standards that are easier to adjust than those used in norm-referenced scoring. Criterion-referenced scoring measures student progress toward mastery of specific criteria, while norm-referenced scoring measures progress relative to percentiles.
Criterion-referenced scoring measures student progress toward mastery of specific criteria, while norm-referenced scoring measures progress relative to percentiles.
Declarative knowledge vs Procedural knowledge
Declarative knowledge refers to factual knowledge and information that a person knows/identifies. Procedural knowledge, on the other hand, is knowing how to perform/execute/ use/explain certain activities
Which statement accurately describes response-code scoring for a traditional test? A student's score is based on all homework and test grades averaged cumulatively. The highest grade earned in a class is given a score of 100, then all other grades are calculated based on that adjustment. The teacher determines the percentage of available points a student earned on each section of a test and then translates that into a score on a proficiency scale. Each answer on a student's test is given a label, and the pattern of labels is used to determine the student's level of proficiency.
Each answer on a student's test is given a label, and the pattern of labels is used to determine the student's level of proficiency.
Response Code
Each student answer is marked with labels, and the pattern of labels is then examined to determine the student's level of proficiency.
How can teachers use proficiency scales to facilitate learning progress? Ask students to use the proficiency scales to evaluate peer assignments aligned with targets in a standard measured on a scale Encourage students to work independently to complete activities aligned with targets in a standard measured on a scale Isolate learning targets within a standard to ensure students understand the connection with activities measured on a scale Explain to students how the learning targets can be used to progress toward a standard measured on a scale
Explain to students how the learning targets can be used to progress toward a standard measured on a scale
Response-code scoring on a test determines a student's level of proficiency by examining patterns of responses using percentages of available points. True False
False
focus statement vs measurement topic
Focus statements are standards rewritten to provide clear focus for assessments. A measurement topic is derived from the focus statement to be assessed multiple times to determine student mastery.
A high school psychology teacher is reviewing the following standard for the curriculum and making note of the measurement topics: Standard Area: Personality 1.1: "Explain how biological and environmental factors interact to influence personality" (American Psychological Association, 2022). Which measurement topic aligns to the given standard? Behavior Cognition Genetics Sociology
Genetics
"Perform a varied repertoire of music by playing instruments, alone and with others, from rote memory and written notation" "Play accurate pitches and rhythms, as modeled and/or visually notated, in tune with a steady beat, good tone quality, and appropriate technique throughout the known range of the instrument(s)" "Play unpitched, melodic, and harmonic instruments with expression and technical accuracy, as modeled and/or visually notated, and portray appropriate style" Which proficiency scale statement measures procedural know The student will play a musical scale with proper technique on a trumpet.The student will read written notation while playing a melody on a saxophone.The student will demonstrate proper fingering technique on a clarinet.The student will demonstrate how to play a standard chord on a violin.
The student will demonstrate proper fingering technique on a clarinet.
A team of teachers is reviewing the English language arts department's standards. The team plans to update proficiency scales to better align with the standards for the curriculum. One standard under review is the following: CCSS.ELA-Literacy.RST.6-8.7: "Integrate quantitative or technical information expressed using words in a text with a version of that information expressed visually using a flowchart, diagram, model, graph, or table" Which proficiency scale statement aligns with developing level 2.0 proficiency for the given standard? The student will describe technical information in a text and integrate it into a diagram. The student, with help, will combine text with a visual image. The student will depict technical information from a text in a table. The student will create a detailed flowchart integrated with technical information.
The student will depict technical information from a text in a table.
A fifth-grade teacher is creating a proficiency scale to assess the following standards: CCSS.ELA-Literacy.RF.5.3: "Know and apply grade-level phonics and word analysis skills in decoding words" (Common Core State Standards Initiative, 2021). CCSS.ELA-Literacy.RF.5.3.a: "Use combined knowledge of all letter-sound correspondences, syllabication patterns, and morphology (roots and affixes) to read accurately unfamiliar multisyllabic words in context and out of context" Which proficiency scale statement measures developing level 2.0 proficiency for the given standards? The student will identify syllabication patterns to successfully read out-of-context unfamiliar words. The student, with help, will demonstrate letter-sound combinations. The student will identify morphology to aid in accurate reading of unfamiliar in-context words. The student will describe phonics and decoding techniques.
The student will describe phonics and decoding techniques.
An English language arts teacher is designing a proficiency scale to assess students' declarative knowledge about the measurement topic of literary concepts. Which proficiency scale statement corresponds to developing level 2.0 proficiency for the given measurement topic? The student will explain how an author's voice impacts a story. The student will predict what would happen if the protagonist and antagonist switched roles. The student will compare multiple stories by the same author. The student will determine the central theme of a story.
The student will determine the central theme of a story.
"Develop a probability distribution for a random variable defined for a sample space in which theoretical probabilities can be calculated; find the expected value. For example, find the theoretical probability distribution for the number of correct answers obtained by guessing on all five questions of a multiple-choice test where each question has four choices, and find the expected grade under various grading schemes" Which proficiency scale 3.0 proficiency for procedural knowledge? The student will develop a probability distribution for a random variable and then find the expected value. The student will understand how to develop a probability distribution for random variables in a sample space. The student will identify a random variable defined for a sample space to calculate theoretical probabilities. The student will describe how to calculate a theoretical probability and then how to find the expected value.
The student will develop a probability distribution for a random variable and then find the expected value.
Procedural knowledge of sentence construction. "Demonstrate command of the conventions of standard English grammar and usage when writing or speaking" "Explain the function of nouns, pronouns, verbs, adjectives, and adverbs in general and their functions in particular sentences" Produce simple, compound, and complex sentences" Which proficiency scale statement measures procedural knowledge at target level 3.0 proficiency for the given standards? The student will create a compound sentence with proper nouns aligned with relevant pronouns in the second clause. The student will format a complex a complex sentence with proper nouns, active verbs, and direct or indirect objects. The student will label the various parts of speech in a compound sentence, including the subject, predicate, and coordinating conjunction. The student will use the possessive form of pronouns in a complex sentence.
The student will format a complex sentence with proper nouns, active verbs, and direct or indirect objects.
Validity
The term validity refers to the degree to which the assessment is relevant and specific to the actual content intended to be measured.
How is a student's true score related to the error score? The true score is an estimate of the actual score if the student had a zero-error score. The true score is the student's score on an assessment after adjusting for the class's average error score. The true score is the average of the student's scores over time minus their highest error rate during that period of time. The true score is the student's error score plus their observed score for that assessment.
The true score is an estimate of the actual score if the student had a zero-error score.
What is a characteristic of parallel assessments? They assess multiple standards. They are administered to different groups of students in order to compare scores. They are administered concurrently to determine reliability. They assess the full scope of a standard or learning objective.
They assess the full scope of a standard or learning objective.
What is a criticism of standards-based grading systems? They do not reflect students' proficiency in soft skills such as time management and creativity. They do not account for student behavior issues, so classroom management is more challenging. They reduce the level of complexity to oversimplified learning targets, so students are not challenged enough. They require more one-on-one instruction, which is not realistic for schools without block schedules.
They do not reflect students' proficiency in soft skills such as time management and creativity.
Which equation represents the relationship between a student's observed score and true score on an assessment? error score = true score + observed score true score = observed score + error score true score = error score - observed score observed score = true score + error score
observed score = true score + error score
