Glossary

  • abstraction

    The use of conceptual categories, such as verbs, pragmatic functions, discourse markers, play behaviors, etc., for analysis, instead of the actual utterance or behavior itself. The definition and identification of any behavior requires some level of abstraction from the actual phenomena.

  • alternating treatment design

    One type of single-case design in which two different treatments are alternately applied within a single treatment phase, to assess the relative effectiveness of each treatment on the client’s performance.

  • alternative explanation

    A different interpretation for the results of an experiment. If a counter explanation for the results can be shown to be plausible, then the internal validity (current causal explanation) of the study is called into question.

  • average

    A measure of the center or central tendency of a dataset. The mean, median and mode comprise three types of averages.

  • baseline data

    Data collected during a baseline phase in which no intervention occurs.

  • baseline phase

    The period of time, in which information on the target problem is collected before initiating formal intervention.

  • benchmark

    A standard or point of reference against which things may be compared or assessed. In Therapy-Science, benchmark lines can span phase boundaries and can be nonlinear. The benchmark tool is located in the settings menu of the graph.
    See: How-To: Make Goals and Benchmarks.

  • between-phase

    comparing the data paths between two treatment phases.

  • boxplot

    The box plot (a.k.a. box and whisker diagram) is a standardized way of displaying the distribution of data based on the five number summary: minimum, first quartile, median, third quartile, and maximum. The central rectangle spans the first quartile to the third quartile, comprising the interquartile range (IQR). The line inside the rectangle shows the median and whiskers extend above and below the box as far out as 1.5 * IQR on each side of the median. Typically they represent the range of the data. However extreme or suspected outlier data points can be identified when they extend beyond the whiskers.

  • case-controlled study

    A type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute. Case-controlled studies are often used to identify factors that may contribute to a medical condition by comparing subjects who have that condition/disease (the “cases”) with patients who do not have the condition/disease but are otherwise similar (the “controls”). They require fewer resources but provide less evidence for causal inference than a randomized control trial. (from Wikipedia)

  • clinic tracking data

    Data collected through direct or indirect observation during clinical encounters.

  • clinical guidelines

    A set of recommendations about the treatment of clients with a specific disorder. Clinical guidelines are based upon systematic reviews and individual research articles, representing best practice guidelines combined with the clinical experience of the reviewers.

  • clinical practice design

    Using a single-case methodology as a guide, a clinical practice design, provides an organized means for implementing and evaluating a client’s performance in a therapy context. Because of dealing with day-to-day, real-world circumstances, clinical practice designs may not be able to adhere to some of the design requirements for establishing causality, stability or other controls characteristic of single case designs.

  • cohort study

    A type of longitudinal investigation in which subjects are grouped by a defining characteristic, such as birth or graduation or disability. Cohorts are then compared cross-sectionally at intervals through time. (wikipedia)

  • communication context

    Settings, situations, locations, etc., in which communication and interaction occur.

  • conclusion validity

    The ability to produce accurate measurements of your observations. Threats to conclusion validity include bias, instrumentation and reliability problems

    Related term: measurement validity

  • Conservative Dual Criteria

    A single-case statistical analysis in which the most conservative contrast (i.e., hardest to reject) based on baseline data, is projected as a line through the adjacent/treatment phase. A binomial statistical test is then conducted to determine if proportion of treatment data above the comparison line is statistically significant. A 0.25 standard deviation in the direction of the predicted treatment effect is added to the baseline line to reduce problems associated with autocorrelation.

  • construct validity

    Addresses the issue whether the intervention works the way it is supposed to work to produce the behavior change, or whether something else does. That is, does the proposed theory or model adequately explain how your intervention produced the results that it did? That is, is the theoretical explanation consistent with its procedural implementation?

  • control data

    Data collected along with treatment data and generalization probes to determine whether treatment progress could be explained by general maturational processes. Control data targets are typically behaviors that generally develop along with target behaviors, but are not expected to be affected by the treatment itself.

  • criteria

    The stated level of a client’s performance that indicates the completion of the goal. In Therapy-Science, the criteria is composed of 4 parts: 1) whether the criteria is above or below the client’s current level of performance, 2) number of successful trials, 3) number of trials in which success will be evaluated, and 4) the criteria level. For more information see How-To: Make Goals and Benchmarks.

  • critical thinking

    The intellectually disciplined process of actively and skillfully conceptualizing, applying, analyzing, synthesizing, and/or evaluating information gathered from, or generated by, observation, experience, reflection, reasoning, or communication, as a guide to belief and action.  (link)

  • data

    The information collected during the course of an evaluation to answer the questions being investigated.

  • data path

    Consecutive points of a data series within a phase.

  • data point

    The visual representation of a single value of the dependent or treatment variable represented on a graph.

  • data series

    One or more phases of a series of data points comprising a single treatment or measurement.

  • data set

    All the data and markup that is included on one single-case design.

  • data tracking plan

    The procedures and techniques used to collect the behavioral data relevant to assessing client performance towards achieving a desired outcome.

  • data-informed

    Using data obtained from one’s client to assess and analyze performance, and make decisions about next treatment steps.

  • direct observation

    The observation and recording of behavior across a variety of contexts (e.g., therapy task, classroom participation, conversation group). In these situations, the practitioner may elicit specific prompts and record the quality of client response, or may do nothing to alter normally occurring spontaneous performance. In either case, the client’s observable behavior serves as the unit of analysis.

  • egocentric thinking

    Taking one’s own point of view as “the truth” before taking into account the needs and beliefs of others. Egocentric decision making is primarily, intuitive, self-centered, and non-reflective.

  • evidence hierarchy

    A ranking of research study types on the basis of their ability demonstrate causal relationships between the intervention and clinical outcome, in order to identify those studies that can eliminate, or are at less risk for systematic error – by design. Evidence hierarchies, by themselves, don’t rate the quality of individual studies.

  • Evidence-Based Practice

    It is the position of the American Speech-Language-Hearing Association that audiologists and speech-language pathologists incorporate the principles of evidence-based practice in clinical decision making to provide high quality clinical care. The term evidence-based practice refers to an approach in which current, high-quality research evidence is integrated with practitioner expertise and client preferences and values into the process of making clinical decisions.

  • expert opinion

    The opinion of a respected authority figure or group obtained through publication or presentation. Expert opinion is not officially sanctioned by an evaluation committee and or based on a formal review of existing research, which is characteristic of a clinical guideline. It is typically considered one the lowest form of research-relevant evidence.

  • external evidence

    Information accessed from research studies. It is the explicit use of valid external evidence (eg, randomised controlled trials) combined with the prevailing internal evidence that defines a clinical decision as “evidence-based.”

  • external validity

    The ability to generalize the results of your study or clinical findings to other contexts (e.g., outside of therapy), behaviors, times, or clients (i.e., with the same or different problems).

  • extraneous variability

    Extraneous variability refers to fluctuations in a client’s performance that are due to influences external to the therapy situation (i.e., context) and not due to treatment. Internal validity threats (e.g., history, maturation, instrumentation, testing, mortality, regression) are likely causes of external variability.

  • functional context

    The contexts that the client normally participates, carrying out their daily activities.

  • functional goal

    Intervention plan components involved in achieving the success criteria in authentic communication situations such as school or work contexts. A functional goal could also focus on taking probe data without doing active intervention. May be short or long-term.

  • generalization

    The ability to extend the results of a specific intervention beyond the treatment setting to non-clinical daily living contexts, to apply to other behaviors or other individuals. (same as carry-over)

  • generalization probe data

    These data are collected outside the treatment context, during functional communication activities in applied and/or naturalistic settings. They address the issue of the application of skills acquired during therapy to real communication contexts and directly address to instrumental outcomes and ultimate outcomes.

  • ghosting

    Removing one or more data points from visual and quantitative analysis while maintaining the data in the client’s record. In Therapy-Science, this is accomplished by enclosing each data point with parentheses. A grayed-out version  of the datapoint will appear on the graph but will not be connected to the other data points in the series.

    Related terms: ghost, ghosted data

  • global assessment

    The evaluation of an individual’s general level of functioning (i.e., psychological, physical, communicative, social, occupational domains).

  • goal

    A strategic program for carrying out an intervention. A goal includes 1) the specification of a treatment target, 2) the ingredients needed to carry out the intervention, 3) mechanisms of action underlying the communication problem, and 4) the planned course of the intervention. (same as goal plan, intervention plan)

  • Goal Attainment Scale

    A composite measure of a client’s progress by organizing a variety of performance evaluation and behavior tracking measures into a coherent description of a client’s improvement over time.

    Related term(s): GAS

  • goal plan

    A strategic program for carrying out an intervention. A goal plan includes 1) the specification of a treatment target, 2) the ingredients needed to carry out the intervention, 3) mechanisms of action underlying the communication problem, and 4) the planned course of the intervention. (same as goal, intervention plan)

  • goal statement

    Defines the behavioral phenomena that you plan to target for intervention, as well as, the procedures, criteria, and other components that comprise the intervention process needed to evaluate clinically relevant behavioral change. In a well-built goal statement, the outcome is operationally defined and evaluated by an explicit criterion, thereby making it testable and falsifiable like a research hypothesis.

  • graff

    A dynamic, interactive, visual analysis tool that allows interaction, data exploration, and data analysis to provide both qualitative and quantitative analysis of the data. Similar to a data graph.

  • granularity

    The scale or divisibility of a behavior into smaller and smaller parts.

  • graph

    A diagram or chart displaying the relationship between variables. A single-case graph shows the relationship between the evaluation of one or more treatments over time.

  • horizontal axis

    The timeline displayed across the bottom of a single-case graph. It is usually marked by sessions, days or weeks. Note that sessions may not represent equal intervals, as the intervals between meeting times may differ. This can impact the visual display of the client’s performance on the graph.

    Related terms: y-axis

  • hypothesis

    A prediction about the performance of the the phenomena under study. A scientific hypothesis makes a specific prediction and is testable, that is, it makes provisions for the ways the hypothesis can be rejected.

  • iGraph™

    A dynamic, interactive, visual analysis tool that allows interaction, data exploration, and data analysis to provide both qualitative and quantitative analysis of the data. Similar to a data graph.

  • indirect observation

    A variety of techniques used to gain information about a stakeholder’s behavior, values, attitudes, etc., summarize one’s own or a stakeholder’s perceptions about the client’s performance or to judgements about the client’s quality of experience. These include diaries, interviews, checklists, individualized rating scales and global assessments.

  • Individualized Rating Scale

    A set of categories designed to capture the distinct qualities of a client’s problem which can be used by the client and others to rate their success over time. They can be used to identify and assess individualized problems across a wide range of clients. Scale items describe an individual’s experiences and are rank ordered.

    Related terms: IRS

  • inference

    Conclusions made about a behavior phenomena during the identification and coding process, based on evidence and reasoning. Low-level inferences involve identifying behavior based on their physical-perceptual attributes. Higher level inferences involve decisions based on the perceived intentions of the speaker/actor (He meant it as an insult.), value judgements, (that was a bad attempt, He didn’t try hard enough), assumed consequences of actions (he went home (the speaker based their assumption on standard practice).

  • instability

    Data characterized with a high degree of variability.

  • instantaneous time-sampling

    An observation time-sampling technique in which the observer only records the behavior that occurs at the endpoint of each time sample. It is good for recording behavioral states, that is, activities that are relatively long in duration such as attending/disattending, talking, reading, playing, hand flapping, etc.

  • instrumental outcome

    Corresponds to the emergence of generalized performance changes that can be observed in other contexts and/or function independently outside the clinic context. An instrumental outcome may consist of the display of a target behavior in an applied context (e.g., client begins to correctly articulate the /s/ phoneme in initial position during conversations with his teacher) or represent a shift in cognitive, emotional or attitudinal stance (e.g., client may pause and reflect before responding to a difficult question). As such, an instrumental outcome may serve as the basis for the attainment of other functional outcomes and best monitored using generalization probes outside the clinic context.

  • intermediate outcome

    The specific behavior or state that believed to be the prerequisite for the client to progress successfully through the intervention process. It represents the objectives that must be obtained in order to achieve the ultimate goal. An intermediate outcome is similar to a short term objective in that both may focus on a specifiable waypoint in a client’s progress. They differing that an intermediate outcome always represents a waypoint towards the achievement of an ultimate outcome.

  • internal validity

    Internal validity relates to the causal linkage between the independent (treatment) variable and the dependent (response or outcome) variable. An internally valid study is one which minimizes the threats to internal validity in order to confidently measure causation.

  • interquartile range

    The interquartile range (IQR) is a descriptive estimate of variability. Dividing a dataset into 4 quartiles, the IQR represents the range between the 25th (1st) and 75th (3rd) quartile, or the inner 50% of the data. The median is the 2nd quartile.

    Related term(s): IQR

  • intervention

    A condition or phase in which the practitioner treats, trains and/or provides technology to resolve the target problem or improve performance.

  • intervention plan

    A strategic program for carrying out an intervention. An intervention plan includes 1) the specification of a treatment target, 2) the ingredients needed to carry out the intervention, 3) mechanisms of action underlying the communication problem, and 4) the planned course of the intervention. (same as goal plan, goal)

  • legend

    A visual key to the data in the graph, linking a meaningful title to the corresponding data series.

  • level

    The average performance within a phase or data path. Therapy-Science uses the median to calculate level because it is less influenced by extreme scores.

  • maintenance phase

    A treatment phase that closely follows the last intervention phase, in which the practitioner provides the client with the strategies for being independently successful, and begins to let the client manage their behavior by themselves. Progress involves both objective and subjective goals.

  • mean

    A measure of the average score, derived by summing up all the values then dividing by total number of values. Compared to the median, the mean influenced more by extreme scores, especially in small data sets. The median is used to calculate Level statistics in TS

  • mechanism-based reasoning

    Makes claims about the functional relationship between inputs (e.g., an intervention) and patient-relevant outcomes, based on assumptions made about the mechanisms involved (Mechanisms are arrangements of parts/features of an observed phenomena that describe a stable relationship between its ‘inputs’ and ‘outputs’). Such reasoning will involve an inferential chain linking the intervention with a clinical outcome.

  • median

    A measure of the average which utilizes the middle value of a distribution of values to represent the average. It differs from the mean, which is derived by summing up all the values then dividing by total number of value. Compared to the mean, the median is less influenced by extreme scores, especially in small data sets. The median is used to calculate Level statistics in Therapy-Science.

  • mental verb

    Verbs that express the intellectual processes or mental states of the speaker, their addressee or anotjer individual who is being talked about (e.g., think, annoy, believe, realize, know, hate).

  • meta-analysis

    A type of systematic review that addresses a defined research question by using statistical methods to summarize the results of a set of studies that fit pre-specified eligibility criteria.

  • moving average

    A statistical technique used to determine a trend in a time-ordered set of data (time series, single case design). In its simple form, a moving average is calculated by averaging initial subset of the data set (e.g., first 3 numbers), averaging successive subsets of the data series by excluding the first number of the previous subset and including the next value in the subset. The trend line that is produced by a moving average smooths out the variability of the data set, while being sensitive to changes in trend within a phase.

  • multiple phase-change design

    A single-case design that consists in making numerous systematic modifications in the goal criteria, task type and/or task difficulty over the course of an intervention. The changing criteria design is a good example of a multiple phase-change design.

  • nonparametric

    A set of descriptive and inferential statistical techniques that do not rely on assumptions that the data are drawn from the normal or other probability distributions. Non-parametric methods are particularly suited for analyzing small and non-normally distributed datasets.

  • observer drift

    A source of measurement error in which accumulated observation experience begins to alter the criteria used by the observer to categorize or evaluate the correctness of observed behavior.

  • operational definition

    Defines the specific process in which behavior is observed and classified, and/or the procedures used in eliciting the behavior (e.g., therapy task) are objectively descrived.

  • operationalize

    The process of defining a behavior by its observable features and the specific techniques used to conduct the observation or measurement of the behavior.

  • outcome

    The expected result of the intervention.

  • outcome plan

    Describes the individual outcome criteria, as well as the proposed relationships between outcome sequences and between treatment and functional outcomes.

  • outlier

    An datapoint that lies an distance from other values in a data path or data series judged to be abnormal or extreme by the analyst.

  • parametric treatment design

    An adaption of single case design in which the client’s response to changes in magnitude levels throughout a single session are recorded.

  • partial time-sampling

    A type of observation time-sampling in which observations are made throughout the entire time-sample. Partial time-sampling is sensitive to recording instances of short duration behaviors, as they will be noted whenever they occur.

  • Percent Non-Overlapping Data

    A quantitative measure that evaluates the proportion of data points in the treatment phase that exceed the most extreme value in the baseline phase. The strength of this analysis is that it is simple and conservative. The two phase series must be largely non-overlapped in order to exceed at least the 70% non-overlap threshold to be considered noticeable.

  • percent non-overlapping data

    The proportion of data points in a particular phase that do not overlap with the datapoints in the preceding phase. Typically this measure is used to assess differences between the treatment and baseline phases. Percent non-overlapping data can be calculated in a variety of ways and serves as the basis Percent-Non-Overlapping Data, Conservative Dual Criteria and Tau-U statistical tests.

  • phase

    The specific course of a treatment. A change in treatment conditions (e.g., shift from baseline to intervention) will result in a phase change.  The concept of phase is synonymous with the terms of  treatment and independent variable.

  • phase length

    The number of data points comprising a data path within a phase.

  • phase line

    A vertical line drawn in a single case graph that marks the boundary between treatment phases. It separates a data series into data paths. In TS a phase line is created by placing a pipe or “|” character between data points in the data window to create two phases.

  • phase series

    Consecutive data points from a data series that fall within a specific phase.

    Related term(s): data path

  • PICO

    PICO is a mnemonic for Patient, Intervention, Comparison, Outcome. These terms provide a framework for asking precise and answerable questions from the healthcare literature.

  • probe

    Data collected outside the treatment context that addresses the generalization of training to other situations and activities. Probe data may be collected in either structured or unstructured context and typically addresses a client’s instrumental outcomes.

  • qualitative

    The meaning and/or reasoning underlying client performance.

  • qualitative analysis

    An interpretative investigation to identify the meaning underlying client performance.

  • quantitative

    The numeric values of a data set.

  • quantitative analysis

    Measuring, describing and analyzing the numeric values of a data set.

  • quasi-experimental design

    In this family of research designs, the treatment and control groups are different at the beginning of the study. Although the study may be of high quality and the findings significant, the design alone does not control for other differences in the two groups which may explain the study’s results.

  • randomized control trial

    A study in which people are assigned at random (by chance alone) to receive one of several treatment conditions, including the experimental treatment and either a different type of treatment or no treatment.

  • reconstructed baseline

    Baseline data developed by interviewing stakeholders about the client’s past performance (e.g., stuttering essential unchanged last 6 months, speaks only 1 word utterances).

  • reliability

    The overall consistency of a test measure or the dependability one’s observations. For example the consistency in which two observers give the same estimates of a given behavior or the accuracy in which a single observer was able to code similar behaviors over time using the same category would be a matter of reliability. Threats to reliability would include observational inconsistency due to lack of training, observer drift and/or vigilance problems.

  • retrospective baseline

    Baseline formed using previous therapy data. Retrospective baselines can be valuable in determining changes over time while participating in therapy.

    Related term(s): archives baseline

  • simple phase-change (A|B) design

    The simple phase-change design (A|B) design is comprised of two phases, typically a baseline (A) phase and a treatment (B) phase. The baseline phase serves as a control to compare against the client’s performance when receiving intervention services.

    Related term(s): A|B design

  • single-case design

    Family of research and evaluation designs characterized by the systematic repeated measurement of client outcomes and regular, frequent, predesignated intervals under different conditions, baseline and intervention, and the evaluation of outcomes over time, and under different conditions in order to monitor client progress, identify intervention fax, and more generally, learn when, why, how, and the extent to which client change occurs. Also known as single–subject design, single–system designs, and N=1 designs, or sometimes time-series or interrupted time-series designs.

  • single-case graff

    The single case graph utility that is included as part of the Therapy-Science subscription service. It is visually modeled after a traditional single case graph, but introduces the interactivity, visual analysis components, and data exploration and analysis capabilities associated with a graff.

  • single-case iGraph™

    The interactive single case graph utility that is included as part of the Therapy-Science subscription service. It is visually modeled after a traditional single case graph, but introduces the interactivity, visual analysis components, and data exploration and analysis capabilities associated with an iGraph™.

  • slope

    Slope (or trend) refers to the direction and degree of change typifying a data path as it moves forward in time. Visually, it can be described as upward or increasing, versus downward or decreasing, or flat (i.e., no trend). Trend can also be gradual versus steep, and immediate versus delayed.

  • sociocentric thinking

    A style of thinking and reasoning that involves one’s rationalization about the world in ways that serve the group with which we are affiliated.

  • speech act

    Those utterances or aspect of an utterance that has performative function in language and communication action, particularly with regard to its intention, purpose, or effect.

  • stability

    Often used in place of variability, emphasizing its functional application to the single case situation (i.e., stable data = low variability, unstable data = high variability).

    Related term(s): spread, drift, dispersion, variability.

  • stability envelope

    The variability of the most stable portion of the data series. It can be estimated using the interquartile range around the median or the variability cloud accessable through the level and trend line functions.

  • statistical significance

    The process of determining whether the probability of the test statistic obtained is more extreme than the probability cutoff value of the null hypothesis (i.e., normal state of affairs). Statistical significance only pertains to the likelihood of occurrence not treatment effect size or real-world importance of the difference.

  • systematic observation

    Organizing an intervention to reduce the potential for bias. This includes developing operational definitions for target behaviors, protocols for administering treatments, objective criteria for evaluating performance, and a tracking plan for scheduling and performing observations. For a single-case design, systematic observations are also performed repeatedly within each phase of the intervention.

  • systematic review

    An external evidence procedure that addresses a defined research question by collecting and summarizing all empirical evidence that fits pre-specified eligibility criteria. A meta-analysis uses statistical methods to summarize the results of these studies. As with any other study, systematic analyses and meta-analyses may differ in quality and focus.

  • target performance

    The target performance or target behavior consists of the behavioral elements relevant to your clinical intervention. It described well enough to be identified and discriminated from other non-target performances in the context in which the intervention is taking place. (link)

  • Tau-U Test of Non-Overlap

    Statistical test that assesses the difference or non-overlap between two adjacent data paths. The advantages of the Tau-U over other tests are that it takes into account the trend of both the baseline and treatment phases, and limits the influence of the baseline trend across the treatment phase based on their respective phase lengths.

  • temporal precedence

    The ability to determine whether the treatment precedes the behavioral observation in time (i.e., the cause precedes the effect). This is a critical component to establishing internal validity.

  • Theil–Sen trend estimate

    A non-parametric method of trend for robustly fitting a line to a set of points that chooses the median of the slopes of all lines through pairs of two-dimensional sample points.

  • time frame

    The duration in which therapy is conducted, event data collected, or the period of time referred to during an interview. Time frames bound the intervention, observation and coding of your client’s performance.

  • time sampling

    A family of methods in which an observation is organized into a series of equal duration time units. Results are reported as the proportion of time units containing at least one instance of the target performance.

  • time-based behavioral measure

    Any measure that explicitly employs time as a property of the measure, such as duration, latency, or time sampling techniques.

  • tracking plan

    Observational strategies and methods used to collect data on a client’s performance in order to evaluate their progress towards the intended outcome.

  • treatment

    A systematically formulated set of principles and procedures that are used to modify and improve client performance.

  • treatment data

    Data gathered while treatment is being conducted.

  • treatment goal

    treatment goal – Intervention plan components involved in achieving the success criteria for a specific treatment target. May be short or long-term in scope.

  • treatment phase

    The specific course of treatment. A change in treatment conditions (e.g., shift from baseline to intervention) will result in a phase change.  

    Related term(s): treatment, independent variable

  • treatment plan

    The written counterpart to an intervention plan, used for clinic documentation. (also therapy plan, plan of care)

  • Treatment-Only Design (B)

    A single-case design that consists of a single phase of treatment data, that is there is no baseline. Changes in intervention can be monitored, but it doesn’t provide information about the source of the behavior change.

  • trend

    The direction and degree of change typifying a data path as it moves forward in time. Visually, it can be described as upward or increasing, versus downward or decreasing, or flat (i.e., no trend). Trend can also be gradual versus steep, and immediate versus delayed.

    Related term(s): slope

  • Tukey Fence

    A nonparametric outlier detection method. It is calculated by creating a “fence” boundary a distance of 1.5 IQR beyond the 1st and 3rd quartiles. Any data beyond these fences are considered to be outliers.

  • ultimate outcome

    Signals the accomplishment of the client’s treatment objectives, which lead to termination from the treatment program. It is similar to the more traditional long-term goal, but is oriented towards program completion and bears a closer hierarchical relationship to constituent objectives.

  • validity

    The extent to which a concept, conclusion or measurement is well-founded and corresponds accurately to the real world.

  • variability

    The fluctuation of performance in a set of data. In single-case design, the term stability is often used in place of variability, emphasizing its functional application to the single case situation (i.e., stable data = low variability, unstable data = high variability).

    Related term(s): spread, drift, dispersion, stability.

  • vertical axis

    Displays the numeric scale (e.g.,frequency, percent, rating) used in the measurement of the target behavior.

    Related term(s): x-axis

  • vigilance

    An individuals ability to maintain sustained and focused attention.

  • visual analysis

    Examining the effects of an intervention at different points over time in order to find discontinuities and other patterns that aid in the interpretation of behavioral change.

  • visual representation

    Representing numerical information visually, usually through graphs. Visual representation tools assist users in finding patterns in data, and making decisions based on those patterns.

  • within-phase

    The data being inspected or analyzed exists within a single phase of the design.