Unit 4 Flashcards
Visual Analysis
A systematic form of data examination, characterized by visual inspection of graphical displays of those data.
In ABA, what does visual analysis allow for?
The evaluation of the effect(s), on behavior, of an experimental or clinical manipulation.
Typically, the data in visual analysis are presented as …
Repeated measurement over time.
Visual analysis involves these two basic processes:
Taking an overview of an entire data display, noting its general characteristics, and specific data inspection and analysis.
What two basic questions does visual analysis answer?
Was there a meaningful change in behavior and to what extent can the change be attributable to a specific environmental change?
Visual analysis has also been termed…
“Criterion by inspection.”
Three types of data display
1 - Data may be embedded in text. 2 - Data may be presented in a summary form, usually as a structured data table (a numerical representation of data). 3 - Data may be presented in a graphical form (a visual representation of data).
What is a graph?
A graph (AKA, “chart”) is a relatively simple visual format for displaying data.
Graphs provide…
Visual representations of relationships between a series of measurements and relevant variables.
Graphs are the major device used for
Organizing, summarizing, interpreting, and communicating the results of ABA.
Graphs provide ____ access to an ______ visual record of behavior and thus promote ____ evaluation.
Graphs provide immediate access to an on-going visual record of behavior and thus promote continuous evaluation.
What can lead to more complete analysis?
Unexpected variation in data.
Visual analysis tends to be _____ than statistical analysis.
More conservative.
Graphs provide visual feedback to
All involved, including the person whose data is being graphed and the individuals who are collecting the data.
What are the four types of graphic displays used in ABA?
Equal-Interval Line Graph, Cumulative Records, Bar Graph (Histogram), and Semi-logarithmic Graphs (e.g. Standard Celeration Chart).
What is the most commonly used graph in ABA?
Equal-Interval Line Graph.
What are four types of graphic displays not used in ABA?
Pie Charts, Area Charts, Radar Charts, and Full-logarithmic “log-log” graphs (log scales on both the X and Y axis).
Equal-Interval Line Graph
AKA The simple line graph. It is based on a Cartesian plan, a two dimensional area formed by the intersection of two perpendicular lines (+ shape)
Cartesian
Invented by Rene Descartes
In a simple line graph, any point within the plan of the chart represents
A specific relationship between the two variables (dimensions) measured along each of the axis lines
For ABA graphs, each point represents
A level (amount) of some quantifiable dimension of a target behavior, measured in relation to some point in time or environmental condition.
Line-graphs are used to
Evaluate treatment effectiveness and also in functional analyses
List the parts of an equal interval line graph
The horizontal x-axis, the vertical y-axis, data points, the data path, condition and phase change lines, condition and phase change labels, and figure legend.
What is the alternative name for the horizontal x-axis
Abscissa
The horizontal X-asis typically represents…
The passage of time
The X-Axis can be marked according to
The needs of the behavior analyst, to promote the most useful analysis.
The X-Axis line can be marked as…
Consecutive calendar days, weeks, or months; or by consecutive school days; or by sessions, classes, or any other specified observation periods, over a period of time.
What is the alternative name for the Vertical Y Axis?
Ordinate
What does the Veritcal Y-Axis represent?
The range of values of the dependent variable (some quantified dimension of the target behavior).
Moving from the zero point upwards along the Y-Axis, each point represents…
An increased value of the dependent variable.
In general, the behavior should be expressed in….
Whole Time Units, such as “per hour” or “per minute” rather than expressed in non-standard units (e.g., “per class” or “per session”).
Problems with non-standard units
Session or class durations can vary, making them difficult to compare.
Generally speaking, for charts of behavior targets for reduction, the Y-axis range should be…
About 1.5 times to 2 times the highest value measured during baseline.
You may have to re-chart your data if….
The target behavior spikes above the Y-Axis range.
What should the Y-Axis range be for acquisition targets?
No convention exists. It depends a great deal on the specific behavior being charted.
For equal-interval line graphs, with clearly defined learning objectives…
Extended the Y-axis range enough above the learning goal to allow for excellence - usually 25% to 33% above.
What can be used to represent different dependent variables?
Different shapes. This is particularly useful in helping to distinguish between data paths.
Data path
A series of straight lines connecting successive data points within a phase or condition.
The data path represents
The relationship between the IV and the DV.
Each line in a data path represents
An estimate of the course taken by the behavior between each point.
Phase changes represent one of two types of occurrence:
- Major changes occur in the independent variable (e.g., the introduction or discontinuation of an intervention).
- A major (usually permanent) change in the environment (e.g., the person moves residences, or sustains a permanent injury).
What is placed at a point along the X-Axis to indicate the point in time when the phase change occurred?
A solid vertical line.
Condition Changes
- Minor changes occur in the independent variable (i.e., a change in some parameter of an on-going intervention).
- A minor (usually temporary) change in the environment (e.g., the person is temporarily ill or goes on vacation).
What is placed at a point in the X-Axis to indicate the point in time when the condition changed?
A dotted vertical line.
Conditions typically change _____
Within phases. Thus, charts may contain only phase change lines, or both phase and condition change lines.
______ now represent both condition and phase changes in the majority of published articles in ABA.
Dotted vertical lines.
The X-axis label states…
What time periods are represented by each successive data point (e.g., days, weeks, sessions).
The Y-axis label states…
What response measure was used to measure the dependent variable - the target behavior (e.g., rate of hits per hour, number of mands)
Phase labels are ____
Brief, placed at the top of the chart, and identify each separate major phase of treatment (e.g., baseline, DRA, D/C Haldol)
Condition change labels ___
Mark changes occurring within a phase (e.g., changes in FR schedule, dosages).
Figure Legend
A concise statement that provides you with sufficient information to identify the dependent variables and the independent variables, and possibly other salient information necessary to visually interpret the data.
What four characteristics of the data plotted on the chart must be looked at when analyzing a graph visually?
Level, variability, trend, and the number of data points.
Level
The mean (or rarely, the median value) of a set of data points
Trend
The directionality of the line drawn through a set of data points
Variability
The bounce of a set of data points within phases or conditions. The extent to which measures of behavior under the same environmental conditions diverge from one another.
The level line
A flat horizontal line drawn through a data set at the average value (mean) of those data points.
Visual inspection of the mean shift in level can
Allow you to evaluate the effect of the change in the independent variable
Generally, the X-axis should be about ____ the times the length of the Y-Axis
1.6. About an 8:5 (or more simply a 4:3) ratio
____ level lines are most common
Mean
Median lines are used especially when
Outlying data points skew the level line in a way that makes it non-representative of the data as a whole.
Trends are always described in terms of
The direction of the path through the data: increasing, decreasing, or zero (no) trend.
Trends are NEVER described as…
“First increasing, then decreasing” (those would be two different trends).
Trends are also described in terms of….
The degree of trend (how rapid is the rate of increase or decrease) and the extend of variability of data around the trend.
Trend Lines
The direction and degree of trend in a series of graphically displayed data points visually represented with a straight line drawn through the data.
Usually the ____ line is used instead of trend line.
Best Fit
The Best Fit Line
A trend line, typically drawn freehand. Bisect the data, with close to an equal number of data points above the line and below the line.
The split-middle line of progress method
A mathematical way to calculate trend.
The split-middle line of progress is sometimes referred to as:
The Quarter Intersect Method.
One of the ways to visually analyze data is to look at…
The presence or absence of an affect on the trend by a phase or condition change.
A change in the independent variable is indicated along…
The X-Axis
To get more confidence in the idea that your minimal data accurately reflect the target behavior, you can:
Chart more data based on shorter collection periods.
A change in trend alone (without a change in level or variability) can…
Constitute a significant change.
The opposite of variability
Stability
The greater the variability, the greater the need for
Additional data.
A general rule of thumb on connecting data points
Do not connect data points across periods (on the X-Axis) where no data exist. (Data lost, data not collected, no opportunity to occur)
Variability is determined around…
A central reference: the trend line.
Variability is not defined by…
The full range of the data set.
The minimum number of data points needed for visual analysis
A bare minimum of three data points. The more variable the data, the more data points are required to make a decision on trend.
Connecting across phase and condition change lines
DO NOT DO IT.
When data on dimensional quantities (such as rate, duration, IRT) are collected during unequal observation periods, those data must be….
Converted into comparable units, such as per minute, or per hour.
Dimensionless quantities (Whole interval, Partial Interval) are always reported as…
Percentages of recorded intervals during which the criterion of the interval was met. Percentages need no conversion to standard units.
The cumulative record (or graph) was developed…
By Skinner as the primary means of data collection and analysis in EAB laboratory research.
Cumulative Recorder
An automated device. When in use, the behavior of the experimental subject creates a graph automatically.
Cumulative Recorder is primarily used in
EAB
Rate in cumulative recording is indicated by
Slope, not Y-Axis value. The slope in the line represents responses per minute.
Problems with cumulative records
- At high rates (slopes above 75-80 degrees), major changes in rate can be very difficult to distinguish.
- Local rates (# of responses for any given session on a long term record) and gradual changes in slope (rate) can be difficult to distinguish.
Bar Graphs
Summarize and compare data for different groups of subjects and/or for different conditions
Bar graphs are also used to compare sets of data which are
Not related to one another by a common underlying dimension by which the horizontal axis can be scaled (time, distance)
Improper use of bar graphs
- Should generally not be used to represent changes in repeated measures over time.
- Should not be used to evaluate client progress on a daily, weekly, or monthly basis.
The vertical (y-axis) of a bar graph usually represents the
Dependent variable
The horizontal (x-axis) of a bar graph represents
A phase, condition, or classification variable
Celeration Charts are used
In precision teaching
The standard celeration chart is also known as…
Standard Behavior Chart or Semi-log 6-cycle chart
Cumulative records are best for
Behaviors where cumulative responses are important (such as saving money or exercise)
Standard celeration charts are best for
Acquisition targets and setting learning objectives
How often should you chart your data?
Regular basis. Daily, or at minimum, weekly. Usually you should place your next data point on the chart as quickly as possible.
Problems in charting
Too many dependent variables, dependent variables difficult to see, charts with units that do not reveal trends
