CCSS: Writing Operational Definitions

WRITING OPERATIONAL DEFINITIONSPreparing Your Students for the Common CorePreparing Your Students for the Common Core

PRESENTED BY:

Mark A. VanHeckeScience Educator and Training ProfessionalEast China, Michigan [email protected]

mailto:[email protected]

CCSS ADDRESSED:

CCSS.ELA.RST.9-10.5 Analyze the structure of relationshipsamong concepts in a text, including amongkey terms (e.g. force, friction, reactionforce, speciation, etc.)

OPERATIONAL DEFINITIONSPreparing for the Common Core

WHAT IS AN OPERATIONAL DEFINITION?

One of the most important distinctions between science and other content areas is the way in which practicing scientists define concepts and communicate their findings and ideas.


We can look in dictionary or the glossary at the back of a textbook and define friction as

‘A force that resists the relative motion or tendency to such motion of two bodies in contact.’

American Heritage Dictionary of the English Language 4th Edition 2000.

This tells us what friction is- but nothing at all about whether friction is occurring or what it does


Ordinary dictionary and textbook glossary definitions often lack the precision needed to understand scientific and technical terms and concepts.


When a word or term is used in a scientific or technical context, its precise meaning must be conveyed so that:

• Students know what it is they are looking for in scientific research or investigative activities

• Numerical values may be assigned to observations. Measurement improves the accuracy and reliability of observations

• Research or investigative activities can be replicated by others


Scientists achieve clarity of meaning in the ideas they work with by operationally defining terms and concepts

An operational definition makes scientific and technical terms and concepts observable by describing how an object or condition is to be recognized or how a particular variable is to be measured


While the average person may be satisfied with a description of a phenomena:

Thirst A distressful feeling caused by a need for water

Courtesy: Metablogs


The scientist would ask ‘How can I tell if I have this?’ and/or ‘How can I measure how much of this?’

OrdinaryDefinitionOf Thirst:

A distressful feeling caused by a need for water

Operational Definition of Thirst:

Nineteen hours without access to water.

Note the emphasis of the operational definition of thirst on the measurable variable of time. The definition describes a criterion from which to determine when thirst exists instead of the more nebulous ‘distressful feeling.’


Here’s another example for you:

OrdinaryDefinitionOf Sleep:

A recurring condition of rest in which there is no conscious thought and the eyes are closed

Operational Definition of Sleep:

The existence of specific brain wave frequencies identified on an EEG during several stages of rest

This operational definition of sleep determines the condition of sleep as ‘specific brain wave frequencies’ during ‘several stages of rest; and the means in which these brain frequencies are to be measured.

SUMMARY

• Scientists define concepts and communicate their findings and ideas using operational definitions

• Operational definitions describe how an object or condition is to be recognized or how a variable is to be measured.

• Operational definitions define what students need to look for in scientific research and lab activities. Once students know what to look for, you can then use operational definitions to structure relationships among different concepts.

WRITING OPERATIONAL DEFINITIONSPreparing for the Common Core

KINDS OF OPERATIONAL DEFINITIONSThere are two kinds of operational definitions. If you viewed my presentation ‘Reading Scientific and Technical Content,’ the names should sound familiar:

Qualitative Operational Definitions are descriptive observations of whether a change occurs as a result of change in an independent variable.

Independent VariableAmount of fertilizer added to cornfield

Dependent VariableAmount of corn that grows in the cornfield

Qualitative Operational DefinitionCorn grows in the cornfield

Qualitative operational definitions are easy to make and record but lack precision and detail

KINDS OF OPERATIONAL DEFINITIONS

Quantitative Operational Definitions are measurements showing how much change occurs as a result of change in an independent variable.

Independent VariableAmount of fertilizer added to cornfield

Dependent VariableAmount of corn that grows in the cornfield

Quantitative Operational DefinitionYields of corn (in bushels) were 60% greater in fields where the fertilizer was used than in those fields where fertilizer was not used

Quantitative operational definitions are more difficult to make and analyze but increase the precision and detail of your findings.

WRITING OPERATIONAL DEFINITIONS

Words such as ‘tree’ and other general nouns denote objects that are not always identical.


First, create subsets of the term or concept you want students to operationally define using observable characteristics that are common to members of the subset;

Trees can be categorized in the subsets of gymnosperms or angiosperms

Students may come across these subset terms during classroom instruction or by reading their textbooks or other assigned reading


Gymnosperms Angiosperms

• Many have needle-shaped leafs• No outer covering around seeds• Wind pollinated• Do not produce flowers• Do not produce fruits• Perennial leaves

• Have flowers at some stage in life• Outer covering enclosing seeds• Deciduous leaves• Include carpel which may produce

fruit• Production of endosperm in seeds

A gymnosperm is a plant having no outer covering around its seeds

An angiosperm is a plant which has flowers at some time during its life.

Operational Definition Operational Definition






A gymnosperm is a plant having no outer covering around its seeds

An angiosperm is a plant which has flowers at some time during its life.


Yes there are many characteristics besides those included in the operational definition- the operational definition in this waydefines the parameters of the assignment/investigation.






A gymnosperm is a plant that does not produce flowers An angiosperm is a plant have an outer covering that encloses their seeds.


You can then use other characteristics of the subsets to develop new operational definitions. This defines what students are to look for, provides a foundation for comparing/contrasting with another subset and reduces cognitive load on students


Let’s try another:

Students are assigned to create an operational definition that will describe the relative age of the sedimentary rock layers shown in the image.

Operational DefinitionIn sedimentary rock layers that have not been disturbed, the oldest rocks are found at the bottom and the youngest layer at the top.

In developing the operational definition, discuss the role of gravity in the superposition of the layers and logical assumptions that older rock beds are found below younger beds if the layers are not disturbed.

SUMMARY

• Operational definitions may be classified as qualitative (descriptive) or quantitative (measured)

• General nouns such as tree, fish, or rock detonate objects that are not always identical. This makes communication difficult in science, where detailed descriptions and precise measurements are needed. Operational definitions are used by scientists to define objects and conditions using observable characteristics and by the measurement of identified variables in lab activities.

• It is important to relate operational definitions derived from text or investigative activities to prior background knowledge and supporting concepts.

TEACHER ACTIVITIESPreparing for the Common Core

TEACHER ACTIVITIES

Imagination and curiosity can turn anything into an adventure-just like I did 50 years ago with this box outside my friend’s home in Mt. Clemens, Michigan.

Like anything else I post, use this presentation as a model for what you want to do in your own classroom. And of course check out my Resource Links on the next page.

YOURS IN SCIENCE!!

Visit www.vanheckescience.comfor free stuff and insight

http://www.vanheckescience.com/

http://www.vanheckescience.com/

CCSS RESOURCE LINKS

http://miccss.org/resources-accordion/Michigan Department of Education Common Core Resources. While this takes more of a ‘train the trainer’ approach it does include some great PowerPoints and documents that will enhance your knowledge of the Common Core.

MARK’S HOT CCSS LINKS

http://www.pinterest.com/search/pins/?q=common%20core%20science&rs=ac&len=19I’m just starting to get into Pinterest and there’s a lot of amazing posts you might want to check out here.

http://miccss.org/resources-accordion/

http://miccss.org/resources-accordion/

http://www.pinterest.com/search/pins/?q=common%20core%20science&rs=ac&len=19

http://www.pinterest.com/search/pins/?q=common%20core%20science&rs=ac&len=19