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Fehlvorstellungen auf der Spur
Brauchen Pflanzen Dünger, um zu wachsen? Bestehen alle Organismen aus Zellen? Und was bedeuten eigentlich die Pfeile in den Darstellungen der Nahrungskette? Die US-Forscher Charles Barman und Mary Stein haben einen Test entwickelt, mit dem geprüft werden kann, bei welchen Fragen sich Fehlvorstellungen in den Köpfen der Schüler verstecken. Hier konkret erläutert am Fach der Biologie, im Internet behandelt der Test auch Fragen aus den Fächern der Chemie, Physik und Geographie.
Stimmt es, dass Pflanzen Sauerstoff benötigen? Charles Barman und Mary Stein haben diese und andere Fragen aus dem Bereich der Biologie angehenden Lehrpersonen (Schulstufe wurde nicht genannt) vorgelegt. Das Resultat: Korrekte Begründungen ("ja, auch Pflanzen brauchen Sauerstoff zur Atmung") lieferten nur 30 Prozent der Befragten.
Insgesamt wurden 60 Prozent der Fragen korrekt mit "richtig" oder "falsch" beantwortet. Wurden allerdings die Erläuterungen zur Antwort mit in die Analyse einbezogen, sank die Erfolgrate auf 55 Prozent. Untersuchungen bei Schülern aus allen Schulstufen haben laut Barman und Stein ähnliche Resultate gebracht. Die beiden Forscher weisen deshalb auf das hartnäckige Bestehen solcher Fehlvorstellungen hin und schreiben: "Es ist wichtig, Schüler immer nach der Begründung zu fragen, wenn es darum geht, Wissen zu testen."
Die Forscher muntern Lehrpersonen auf, den Test in der einen oder anderen Form im Unterricht einsetzen, um allfällige Fehlvorstellungen der Schüler zu entdecken. Oder sich schlicht nochmals die Frage zu stellen, wie die angesprochenen Themen im eigenen Unterricht behandelt werden.
Insgesamt 44 Fragen aus den Fächern der Biologie, Chemie, Physik und Geographie sind auf dem Internet zugänglich, in Form eines Quizzes, das man gleich selbst durchführen kann. Wer alle 44 Fragen beantwortet hat, bekommt die Auswertung und die korrekten Erläuterungen zu sehen.
https://www2.oakland.edu/secure/sbquiz/
Tabelle (nur Bereich Biologie) aus: The Science Teacher, March 2008, Vol 75, Nr. 3, pp 68-69
| Item |
Statements presented to students |
(% answered correctly) |
Accepatable written response |
Source of Item |
| 1 |
The only ingredients that plants need to grow are: water, sunlight, and nutrients. |
False (56%) |
Plants also need air to grow. Organisms have basic needs. Plants require air, water, nutrients, and light (K–4 Content Standard [NRC 1996, p. 129]). (Although most individuals understand that plants need water, nutrients, and light, many do not understand how and why certain components of air are essential.) |
(Harvard- Smithsonian Center for Astrophysics 1997) |
| 2 | Plants use oxygen. |
True (29%) |
Aerobic cellular respiration is a biochemical process that occurs in nearly all cells. Plant cells use oxygen during cellular respiration to break down molecules of food to release energy used for building new cells and other cellular processes. |
(Haslam and Treagust 1987) |
| 3 |
The only factors that are necessary for a plant seed to germinate (sprout) are water and a certain temperature range. |
True (22%) |
The seed contains a seed coat for protection, endosperm tissue for food, and the plant embryo. As long as the seed is exposed to moisture and the appropriate temperature range, it has all of the components needed to germinate. The embryo is able to obtain food from the endosperm tissue. As the embryo grows, the endosperm tissue is no longer essential because the sprouting plant begins to make its own food via photosynthesis. |
(Barman et al. 2003) |
| 4 |
In order for a plant to grow, you need to provide the plant with fertilizer. |
False (80%) |
Plants are capable of making their own food through the process of photosynthesis. Although plant fertilizer makes certain nutrients available to plants, unless the medium in which the plants are growing is completely sterile, plants will obtain the energy they need for growth from the food they produce. |
(Barman et al. 2003) |
| 5 |
All animals depend on plants. |
Ttrue (43%) |
According to the Standards, students in grades K–4 should understand that all animals depend on plants, with some animalseating plants and other animals eating animals that eat the plants (K–4 Content Standard [NRC 1996, p. 129]). |
(NRC 1996) |
| 6 |
The arrows of a food chain symbolize the transfer of energy from one organism to another (e.g., grass→ mouse→ snake→ hawk). |
True (46%) |
In a food chain, each organism represented symbolizes a population of that type of organism. The first population makes up the first trophic level (plants or producers), the second is the next trophic level (consumers), and so on. The arrows point from one trophic level to the next, signifying the energy that is transferred between these trophic levels. According to the Standards, students in grades 9–12 should understand that “energy flows through ecosystems in one direction, from photosynthetic organisms to herbivores to carnivores and decomposers” (9–12 Content Standard [NRC 1996, p. 186]). |
(Barman and Mayer 1994) |
|
7 |
If the producers (plants) disappeared from Earth, organisms that prey on other organisms for food (carnivores) would only be slightly affected. |
False (77%) |
If plants disappeared from Earth, the organisms that eat plants (herbivores) would begin to die. Gradually, the carnivores that prey on the herbivores would also start to die from lack of food. |
(Barman and Mayer 1994) |
|
8 |
Humans, dogs, fish, worms, and insects are all considered to be animals. |
True (38%) |
The animal kingdom contains a diverse group of organisms, including those with backbones (vertebrates) and those without backbones (invertebrates). A combination of a few features distinguishes animals from other organisms: animals have cells with defined nuclei and no cell walls, they are composed of many cells, and they are not able to make their own food. |
(Barman et al. 2000) |
|
9 |
Organisms that possess locomotive structures (e.g., movement capabilities) and are able to reproduce are classified as animals. |
False (47%) |
Although locomotive structures and reproductive behavior are features attributed to animals, they are not exclusive to these organisms. Some organisms such as protists (e.g., ciliates and flagellates) and certain bacteria also exhibit these features. |
(Barman et al. 2000) |
|
10 |
All organisms are composed of cells. |
True (89%) |
All organisms are composed of cells—the fundamental unit of life. Most organisms are single cells; other organisms, including humans, are multicellular (5–8 Content Standard [NRC 1996, p. 156]). |
(NRC 1996) |
|
11 |
Reproduction is a characteristic of all living systems. |
T (74%) |
Reproduction is a characteristic of all living systems; because no individual organism lives forever, reproduction is essential to the continuation of every species. Some organisms reproduce asexually; other organisms reproduce sexually (5–8 Content Standard [NRC 1996, p. 157]). |
(NRC 1996) |
|
12 |
Sexually produced offspring can be identical to either of their parents. |
False (70%) |
Sexually produced offspring are never identical to either of their parents. An egg and a sperm unite to begin development of a new individual. That new individual receives genetic information from its mother (via the egg) and its father (via the sperm) (5–8 Content Standard [NRC 1996, p. 157]). |
(NRC 1996) |
|
13 |
Extinction of species of organisms is common. |
True (45%) |
T (45%) Extinction of species is common; most of the species that have lived on Earth no longer exist. Extinction of a species occurs when the environment changes and the adaptive characteristics of a species are insufficient to allow its survival. Fossils indicate that many organisms |
(NRC 1996) |
Quelle:
Charles Barman, Mary Stein: Assessing Basic Knowledge in Biology
The Science Teacher, March 2008, Vol 75, Nr. 3, pp 67-70
Link:
Science Beliefs Quiz
https://www2.oakland.edu/secure/sbquiz/
17. März 2008
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