Opinions on elementary school science homework

[SciFi]

Hi all. I'm reviewing my daughter's science homework and I disagree with how things are being presented. I wanted some feedback from everyone here to get a sanity check on my own thinking. The exercise is this: answer whether these properties of matter are either an observable property or a measurable property: shape, texture, odor, length, state, sink/float, weight, temperature, magnetic, volume, density, mass.

1. I have a problem with the "or". If we cannot observe a property, how could we ever measure it? The act of measuring requires observation. I can observe whether something's solid, but I can also measure it according to different criteria (e.g., the rate of molecular translation, etc.); I can observe something's texture, but I can also measure it (usually via lasers these days); etc.

2. sink/float: these are actions: verbs, not nouns or adjectives. How can these be properties? Density is a property, but sink/float depends on the density compared to that of the fluid it's in (among other things). It's like asking if sit/run or ascend/descend are observable properties or measurable properties. They are actions to be observed or measured, but not properties of the matter itself.

3. weight: weight is a force, not a property of matter. That is, changing the curvature of spacetime in which a mass resides changes its weight accordingly without any change to the mass itself (although the consequence of the modified force might change the mass). No?

4. more generally, isn't any observable property also measurable? If we can observe it, we can visually measure it, even if this form of measurement is highly imprecise. It seems to me "observable" and "measurable" are not mutually exclusive.This seems like a poor exercise to teach scientific concepts: am I crazy and/or ignorant (NOT mutually exclusive)? Thanks for any opinions.

 

[phinds]

I completely agree w/ you.

 

[TSny]

This is likely to generate some interesting discussion. The question is open to interpretation. We don't know how the teacher talked about "observable" and "measurable".

It does seem that there are properties that would be both observable and measurable. As a guess, it could be that "measurable" is meant to denote a property that is quantifiable so that you can assign a numerical value and a unit. There might be properties that are observable but not measurable in that sense. For example, "taste".

There might also be properties that are measurable but not observable, depending of course on the definition of "observable". For example, the wavelength of a certain color of light is measurable. But one might say that the wavelength is not observable. To measure the wavelength, you could pass the light through a prism and observe where the light strikes a screen. You measure things like the distance from the prism to the screen and then deduce with calculation what the wavelength must be. But you are not really observing the wavelength itself.

 

[kuruman]

Let's talk about motion that is not one of the items on the teacher's list. Is motion observable? Absolutely yes. You can tell if something is moving just by looking at it. Is motion measurable? I am not sure. I can measure the object's speed and acceleration and predict where it will be in the future, but have I measured motion? I would say no. What about odor? I think that is an observable, I can tell if something smells nice of if it stinks. Furthermore, something that is stinky to me may smell OK to someone else. Sure we can measure the percentages of chemicals that make up an odor, but if we do, have we observed odor? What is the best way to decide whether something is stinky, look at a list of chemicals (measure it) or just smell it (observe it)? Perhaps the teacher wants to make a distinction between items that can be quantified with a single measurement (mass, length, temperature ...) that are informative and items that can be quantified by a number of measurements (shape, texture, odor ...) that are not very informative about the nature of the item.

I am not sure that this is such a poor exercise to teach scientific principles. There are lot of people out there with fuzzy thinking. The teacher's next step may be to say to the class, "OK, we are doing science here and we need to be precise about how to think of the world. Items such as odor, texture and shape have a place in the English language to describe properties of objects, but they are not important in a science class where the goal is to measure properties of objects and see how they fit in our understanding of the world."

Your obvious course of action is to talk to your daughter's teacher and see where he/she/ze is going with this.

 

[SciFi]

Thanks for the feedback. I definitely agree it's open to interpretation, although I really don't see how "sink/float" could be considered a physical property. Googling around I do see weight often listed as a physical property, but that still seems like a force to me, not a property of matter.

If "measurable" does mean something quantifiable with a number and unit of measurement, wouldn't everything be measurable? To take "taste" as an example, we could define a system of measurement to denote saltiness, bitterness, sweetness, etc., and thereby measure how something tastes, couldn't we? Such as taste = pH * scoville heat unit (etc).

If "observable" means whatever can be seen with the naked eye, then length, mass, light, etc., are both observable and not observable, which would seem to render the term meaningless. I can see certain lengths with my naked eye, but not tiny or monstrous lengths; I can see mass within a certain range but not outside that range; as you point out above we can all view certain types of light but not others (unless you're blind or wear eyeglasses or are color blind, etc.). It seems such as vague term as to lose meaning for me. Schroedinger's Observability Coefficient: the magnitude to which an observable property of matter can be both observable and not observable. :)

Just trying to learn along with my daugher, so thanks for the help. :)

 

[phinds]

Thanks for the feedback. I definitely agree it's open to interpretation, although I really don't see how "sink/float" could be considered a physical property. Googling around I do see weight often listed as a physical property, but that still seems like a force to me, not a property of matter.

Although I agree w/ you, keep in mind that that might be considered a bit too advanced for elementary school. Not sure. Just sayin'

 

[SciFi]

Is motion observable? Absolutely yes. You can tell if something is moving just by looking at it.

Hmmm, I dunno. I've seen objects in space that I'm told are moving, but I would never know that even though I'm staring intently at them. I would need some frame of reference to compare the object to to know it's actually moving. That is, measure its distance compared to something else over time, even if my eyeball measurements aren't very precise.

Your obvious course of action is to talk to your daughter's teacher and see where he/she/ze is going with this.

Yes, I'm asking very nicely for some clarification from the teacher. This homework was given today and is due tomorrow and is already complete, I was just curious what others thought.

 

[Bystander]

Yes, I'm asking very nicely for some clarification from the teacher. This homework was given today and is due tomorrow and is already complete, I was just curious what others thought.

Keep us posted on this please.

 

[SciFi]

Although I agree w/ you, keep in mind that that might be considered a bit too advanced for elementary school. Not sure. Just sayin'

Good point. I try very hard not to confuse my daughter with concepts that aren't appropriate for her age level.

 

[kuruman]

Hmmm, I dunno. I've seen objects in space that I'm told are moving, but I would never know that even though I'm staring intently at them. I would need some frame of reference to compare the object to to know it's actually moving.

Sure, you look up at these objects and you observe that they are not moving. The fact that you were mistaken does not mean that motion is not observable.

 

[haruspex]

If we cannot observe a property, how could we ever measure it?

Some of the attributes we experience directly (shape, texture, taste, odour, weight) while others we only infer from observation of other attributes (magnetism, density). Mass I would put in the first group.
I think this accords with TSny's comment.

weight is a force, not a property of matter

Several in the list are properties of objects (extrinsic) rather than the material of which they are made (intrinsic), so I agree it would be better to call these properties of objects rather than properties of matter.

isn't any observable property also measurable?

At one level, yes, if you can observe it then you can invent a measure for it, even though the measurement may be partly subjective, such as shape.
I hope the teacher does not intend to get into qualia: is your experience of redness the same as mine?

 

[Dr. Courtney]

I'm not a fan of the oversimplifications often made in elementary school science. But change and improvement is likely an uphill battle since in most cases those creating elementary science curricula view being an expert in elementary education as 10 times more important than being a subject matter expert. They often have convinced themselves that the oversimplifications and inaccurate descriptions are necessary for learning at those ages and they shift the burden to later science courses to provide greater accuracy.

My first step would be to determine if the inaccuracies at hand originate with the textbook or with the teacher. If the book gets it right, at least you can point to the textbook for the proper descriptions. But if the book gets it wrong, you have an uphill battle providing clarification beyond your own daughter.

 

[ZapperZ]

I'm usually a stickler for accuracy and proper terminology. But I have to disagree with most folks here on this one.

We need to put things in context here. This is for an elementary science class, and the teacher is using "ordinary" language to ask the students these questions. Therefore, the word "observable" in everyday language means "can be seen with your own eyes", while "measurable" means that "you might not see it easily with your eyes, but you can measure some quantity associated with it".

From what I can "see", the aim here is for the students to realize that there are things about our world that we can directly see with our eyes, but there are also other properties in which we cannot obtain as directly, and can only be obtained via some measurement. We really cannot expect students at that level and that age to be able to use our accurate, scientific language for this exercise. They'll be tied up on trying to understand the language and the whole intention of the exercise will be lost.

Zz.

 

[symbolipoint]

Hi all. I'm reviewing my daughter's science homework and I disagree with how things are being presented. I wanted some feedback from everyone here to get a sanity check on my own thinking. The exercise is this: answer whether these properties of matter are either an observable property or a measurable property: shape, texture, odor, length, state, sink/float, weight, temperature, magnetic, volume, density, mass.

1. I have a problem with the "or". If we cannot observe a property, how could we ever measure it? The act of measuring requires observation. I can observe whether something's solid, but I can also measure it according to different criteria (e.g., the rate of molecular translation, etc.); I can observe something's texture, but I can also measure it (usually via lasers these days); etc.

2. sink/float: these are actions: verbs, not nouns or adjectives. How can these be properties? Density is a property, but sink/float depends on the density compared to that of the fluid it's in (among other things). It's like asking if sit/run or ascend/descend are observable properties or measurable properties. They are actions to be observed or measured, but not properties of the matter itself.

3. weight: weight is a force, not a property of matter. That is, changing the curvature of spacetime in which a mass resides changes its weight accordingly without any change to the mass itself (although the consequence of the modified force might change the mass). No?

4. more generally, isn't any observable property also measurable? If we can observe it, we can visually measure it, even if this form of measurement is highly imprecise. It seems to me "observable" and "measurable" are not mutually exclusive.This seems like a poor exercise to teach scientific concepts: am I crazy and/or ignorant (NOT mutually exclusive)? Thanks for any opinions.

SciFi, this is just my impulsive reaction from seeing only your first two paragraphs:
Kids in just elementary school are not ready for critically studying sciences or "science". You, an adult and much more developed, can more capably be critical. The kids are generally not ready. Someone is assigned the work of trying to prepare the kids. Help yours the best that you can but do not be mean to them nor to their teacher.

 

[symbolipoint]

SciFi, you reported this:

3. weight: weight is a force, not a property of matter. That is, changing the curvature of spacetime in which a mass resides changes its weight accordingly without any change to the mass itself (although the consequence of the modified force might change the mass). No?

I would hate to tell you about something similar that I complained about for getting into trouble myself in the future. When I spoke up years ago, colleagues told me I was too critical and expecting too much.

 

[symbolipoint]

Take this idea: Science education gets better in and after high school.

 

[Dr. Courtney]

I'm usually a stickler for accuracy and proper terminology. But I have to disagree with most folks here on this one.

We need to put things in context here. This is for an elementary science class, and the teacher is using "ordinary" language to ask the students these questions. Therefore, the word "observable" in everyday language means "can be seen with your own eyes", while "measurable" means that "you might not see it easily with your eyes, but you can measure some quantity associated with it".

From what I can "see", the aim here is for the students to realize that there are things about our world that we can directly see with our eyes, but there are also other properties in which we cannot obtain as directly, and can only be obtained via some measurement. We really cannot expect students at that level and that age to be able to use our accurate, scientific language for this exercise. They'll be tied up on trying to understand the language and the whole intention of the exercise will be lost.

Zz.

I would prefer to describe things as qualitative and quantitative rather than observable and measurable. Integrating math as much as possible (through quantitative measurements) in elementary science 1) provides additional opportunities to practice and see the usefulness of math and numbers 2) prepares students better for middle school science when they will encounter formulas and quantitative predictions and 3) better prepares students for the physical sciences that are dominated by quantitative thinking.

I've worked with enough elementary school students to know that most will grasp the distinction between observations to which a number can be assigned (through measurement) and observations which are more difficult to assign a number in a meaningful way long before they reach the 6th grade. Of course, the discussion in K and 1 is much different from 5th and 6th grades. Still the ideas of whether or not a number can be assigned to an observable is key to both math and science as soon as the necessary math foundation is in place.

 

[ZapperZ]

I would prefer to describe things as qualitative and quantitative rather than observable and measurable.

But now you're talking about different things. The original question isn't a matter of PREFERENCE. We all have different ways of doing things and thus, different preferences in these things. Rather, the OP had strong opinions that these things are wrong!

I argue that based on the level of understanding and what the INTENT of the exercise was, I do not see it being wrong. That is my preference.

Zz.

 

[Dr. Courtney]

But now you're talking about different things. The original question isn't a matter of PREFERENCE. We all have different ways of doing things and thus, different preferences in these things. Rather, the OP had strong opinions that these things are wrong!

I argue that based on the level of understanding and what the INTENT of the exercise was, I do not see it being wrong. That is my preference.

Zz.

For me, the degree of wrongness depends on the specific grade - such an inaccurate oversimplification is a lot more wrong for 6th graders than for 1st graders. But since the OP did not give a specific grade, I decided to speak in terms of better and worse approaches (shades of gray) rather than the black and white of right and wrong.

But all teachers would do well to consider whether their approach is going to help or hinder learning downstream. Making the error (and it IS an error) for 1st graders is much more correctable before they hit middle school than making the error for 6th graders.

 

[ZapperZ]

For me, the degree of wrongness depends on the specific grade - such an inaccurate oversimplification is a lot more wrong for 6th graders than for 1st graders. But since the OP did not give a specific grade, I decided to speak in terms of better and worse approaches (shades of gray) rather than the black and white of right and wrong.

But all teachers would do well to consider whether their approach is going to help or hinder learning downstream. Making the error (and it IS an error) for 1st graders is much more correctable before they hit middle school than making the error for 6th graders.

No, I do not see the CLEAR error here. Let's re-read the original question:

answer whether these properties of matter are either an observable property or a measurable property: shape, texture, odor, length, state, sink/float, weight, temperature, magnetic, volume, density, mass.

That is the original question. The REST of the first post were based on the OP's interpretation of what he/she thinks is the problem with the question.

So how exactly can you pick out the error in that question? You have to first anticipate at what the correct answers should be from the teacher, and then show why, beyond just a matter of semantics and interpretation, that the answers are outright wrong.

Zz.

 

[haruspex]

No, I do not see the CLEAR error here. Let's re-read the original question:

You don't think it erroneous to call length a property of matter? (As opposed to a property of space or of objects.)

 

[ZapperZ]

You don't think it erroneous to call length a property of matter? (As opposed to a property of space or of objects.)

No. "matter" at that level are simply "objects", and objects have lengths.

Zz.

 

[haruspex]

This is for an elementary science class, and the teacher is using "ordinary" language to ask the students these questions.

No, the teacher did not use ordinary language, but should have.
What learning is the teacher imparting? Using terms like observable and measurable gives the impression that these are defined in the scientific lexicon, and the correct answers to the questions will illustrate these meanings. If the intent is to get students to appreciate the difference between direct observation and inference it would have been better to use the everyday language equivalents that you propose.

 

[haruspex]

No. "matter" at that level are simply "objects", and objects have lengths.

Zz.

I disagree. As with my previous response re "observable" and "measurable", "matter" is a technical term not an everyday one, so should be used accurately. If a non-technical interpretation is intended just say "things".

 

[ZapperZ]

No, the teacher did not use ordinary language, but should have.
What learning is the teacher imparting? Using terms like observable and measurable gives the impression that these are defined in the scientific lexicon, and the correct answers to the questions will illustrate these meanings. If the intent is to get students to appreciate the difference between direct observation and inference it would have been better to use the everyday language equivalents that you propose.

Again, saying it can be done in a "better" way is a matter of preference! But it doesn't necessarily mean that it is wrong. I'm NOT arguing that things might have been better presented. But then again, when I look at questions that I've given out even a month ago, I can find ways to improve them and make them clearer.

And I'm not certain that the teacher isn't using "ordinary language". It certainly isn't the scientifically strict language that we normally use. What can the students at this level understand and comprehend? Have you checked with students at this level, or the ones being given the problem, if they have the same issues as you did in understanding what is being asked?

Zz.

 

[ZapperZ]

I disagree. As with my previous response re "observable" and "measurable", "matter" is a technical term not an everyday one, so should be used accurately. If a non-technical interpretation is intended just say "things".

I disagree. "Matter" in the "technical term" is WAY more complicated than even many of us can comprehend. Just do a search on "what is matter?" in this forum alone! I hate to think that we expect THAT kind of sophistication from elementary school students!

Zz.

 

[symbolipoint]

What amazing unproductive arguing. Main original question from SciFi, this:

The exercise is this: answer whether these properties of matter are either an observable property or a measurable property: shape, texture, odor, length, state, sink/float, weight, temperature, magnetic, volume, density, mass.

YOUR goal as one of the parents is tell your child which of each is observable and which measurable; explain as needed.

 

[SciFi]

Thanks all, I appreciate the different viewpoints. So my daughter got 3 answers marked wrong on her homework. My daughter answered:

shape, texture, odor, state, length = observable
sink/float, weight, temperature, magnetic, volume, density, mass = measurable

According to her teacher, "length" is not observable: you must have a tool to determine length and therefore it is a "measurable" property of matter. Further, "sink/float"(?) is not measurable because observation is sufficient to determine whether something is sinking or floating: no tools required. Lastly, "magnetic" does not need a tool to determine this property: our senses are sufficient to determine the magnetic property of matter. She says that an observable property of matter is one that does not need a tool to be determined: our senses are sufficient; measurable properties of matter are those that cannot be determined with our senses: we must create a tool.

I disagree with this reasoning. However I need to pick my battles, so I simply thanked her for the clarification and explained to my daugher why I disagree with some of what her teacher explained. I still believe this exercise was poorly worded and does a disservice towards teaching science because it adds unnecessary confusion, which turns kids off science.

 

[Mark44]

According to her teacher, "length" is not observable: you must have a tool to determine length and therefore it is a "measurable" property of matter. Further, "sink/float"(?) is not measurable because observation is sufficient to determine whether something is sinking or floating: no tools required. Lastly, "magnetic" does not need a tool to determine this property: our senses are sufficient to determine the magnetic property of matter.

Really? Which of our five senses can we use to tell if an object is magnetic? I understand that birds can navigate by means of a part of their brain that can detect magnetic currents, but I'm not aware that humans have this ability. In any case, "observable" really should be "sensible" -- whether we can use one of our senses to determine whether an object has a particular attribute.

She says that an observable property of matter is one that does not need a tool to be determined: our senses are sufficient; measurable properties of matter are those that cannot be determined with our senses: we must create a tool.

To determine whether an object sinks or floats, I use a tool labelled "sinks" and "floats" with no other marks. I use this to "measure" the ability of an object to float in water.

 

[haruspex]

I still believe this exercise was poorly worded and does a disservice towards teaching science because it adds unnecessary confusion, which turns kids off science.

I agree completely.
I can observe weight and temperature by holding the object, mass by trying to throw it, volume and length by looking at it. True, I cannot assign numerical values without an agreed yardstick, but that requirement is not made clear in the question.
How is the student to know that the texture, odour and magnetism assessments do not require numerical answers? See e.g. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.1963.tb00217.x/abstract.

 

[haruspex]

YOUR goal as one of the parents is tell your child which of each is observable and which measurable; explain as needed.

But the first hurdle is to guess what the teacher has in mind. Seems it was the distinction between quantitative measures and qualitative ones - hardly clear from the question, and debatable for several of the parameters.

 

[SciencewithDrJ]

I had a similar experience a couple of years ago. My grandson, in grade 5 - in Canada - at the time, invited me to join his class because the teacher held a parent-student competition. Parents were invited to compete against their children in science. Even with a PhD in microbiology and biochemistry, I failed the test and did not pass, because my perspective on answers was totally different. For example, a question was "Sunlight is turned into sugar by plants, TRUE or FALSE. My answer was FALSE, of course, because carbon dioxide and water turn into sugar with the energy supplied from sunlight, but sunlight itself can never turn into sugar. But I failed, because the right answer (according to the teacher) was TRUE. I told the teacher later on and she insisted that I was wrong. There were many other similar erroneous questions and answers, and I failed miserably. My grandson was very disappointed in me, thinking that I really didn't know "my stuff" and I failed.

How do you deal with that? Sometimes, over simplification can be deleterious.

It is unfortunate that the quality of science education in schools lags far behind. The teachers themselves need refresher courses in science. When I taught undergraduate courses in microbiology years ago, my fresh out of high school students literally knew nothing and I almost had to start from scratch.

 

[symbolipoint]

I had a similar experience a couple of years ago. My grandson, in grade 5 - in Canada - at the time, invited me to join his class because the teacher held a parent-student competition. Parents were invited to compete against their children in science.

Let's have an informal vote. How many members reading disapprove of that competition?

 

[symbolipoint]

I had a similar experience a couple of years ago. My grandson, in grade 5 - in Canada - at the time, invited me to join his class because the teacher held a parent-student competition. Parents were invited to compete against their children in science. Even with a PhD in microbiology and biochemistry, I failed the test and did not pass, because my perspective on answers was totally different. For example, a question was "Sunlight is turned into sugar by plants, TRUE or FALSE. My answer was FALSE, of course, because carbon dioxide and water turn into sugar with the energy supplied from sunlight, but sunlight itself can never turn into sugar. But I failed, because the right answer (according to the teacher) was TRUE. I told the teacher later on and she insisted that I was wrong. There were many other similar erroneous questions and answers, and I failed miserably. My grandson was very disappointed in me, thinking that I really didn't know "my stuff" and I failed.

How do you deal with that? Sometimes, over simplification can be deleterious.

It is unfortunate that the quality of science education in schools lags far behind. The teachers themselves need refresher courses in science. When I taught undergraduate courses in microbiology years ago, my fresh out of high school students literally knew nothing and I almost had to start from scratch.

I had earlier said not to be mean to the teachers, but now after this here quoted post, some assignments are seriously badly misguided. PTA or something? Other scientificly educated and experienced parents in the neighborhood? Complain to the school administration.

 

[haruspex]

five senses

Sight, sound, touch, pain, temperature, taste, balance, proprioception, smell, itchiness, hunger, thirst, nausea, ... not to mention familiarity, fear, fatigue, ...
Of course, we did learn in school that we have five.