Long-term study

A long-term study is a methodical and often experimental scientific study that serves to empirically obtain information (data). It spans a long period of time because the phenomenon to be observed rarely occurs or its change is slow. The experimental setup is usually not changed during this investigation period.

A distinction must be made between two types of long-term investigation:

• the long-term study (i.e. the "pure observational study", for example in the fields of sociology, psychology, medicine), in which the observed system is not interfered with,
• and the long-term experiment (in the sense of an "intervention study"). A distinction must be made between the long-term experiment and the mere scientific observation (in the sense of a “long-term measurement”, as is common in astronomy, geology, and biology, for example).

introduction

Long-term studies are required and carried out in many sciences, for example in natural sciences , agricultural and engineering sciences , medicine , psychology and sociology . In medicine, instead of long-term studies, one often speaks of cohort study , while in sociology, it is often referred to as longitudinal study .

Long-term investigations face special, time-related challenges:

• Change of staff : The duration of the long-term examinations usually exceeds the time periods in the sciences in which master, diploma or doctoral theses are written; Even the supervision by the chair holder or permanently employed scientific specialists can often not be guaranteed in long-term studies.
• Stability of the measurement system : During the investigation period, it must be ensured that the experiment performance, i.e. H. Do not change the behavior and properties of the measuring system (e.g. programs (software) or devices (hardware)) so that consistent data acquisition is guaranteed.
• Long-term archiving : Furthermore, sustainable data archiving must be ensured over the entire study period, which can span several decades.
• Attractiveness : By definition, long-term studies do not offer any scientific results that can be determined in the short term, but that makes them unattractive for scientists who have to position themselves strategically for reasons of personal career planning and are therefore particularly attracted to scientific areas that are developing more dynamically and promise opportunities for success in the short term.

Despite these systemic difficulties, long-term studies are carried out in various scientific fields because they often offer the only possibility of verifying or falsifying hypotheses.

The most impressive example of this is perhaps the long-term measurements made by various transnational institutions in meteorology over a period spanning many decades, which meanwhile form the basis for the scientific database on global warming .

Examples of long-term studies

Long-term studies

• The Grant Study (initially sponsored by department store millionaire WT Grant and therefore named after him) , which since 1939 has medically and psychologically monitored a total of 268 Harvard graduates born in 1910 from university to retirement (according to the start of the study, the Subjects are male, white and are US citizens).
• The Horticulture Agriculture and on the faculty of the Humboldt University of Berlin -scale long-term field experiment D III to land use, by Kurt Opitz in 1923 in the newly created test field in Berlin-Dahlem was created with the aim of detecting a mobilization of soil phosphoric acid by purely to provide agricultural measures and at the same time to examine the effectiveness of differentiated phosphorus fertilization under these conditions, and ran until recently.
• The Framingham Heart Study began in 1948 to systematically examine the population of a city ( Framingham , Massachusetts ) for the causes and risks of coronary artery disease (CHD) and arteriosclerosis .
• The DONALD study (abbreviation for: DO rtmund N utritional and A nthropometric L ongitudinally D esigned), which was started in 1985 at the Research Institute for Child Nutrition (FKE). It is an open long-term cohort study in which as many new infants are recruited every year as young adults complete the core study. Close-knit examinations from infancy to adulthood are planned, with detailed data collection on nutrition, growth, development, metabolism and health status.
• Findings of the New Zealand long-term cohort study Dunedin Multidisciplinary Health and Development Study in the medical-genetic area were documented in the film " Long-term study man ".

Long-term measurements

• Long-term meteorological measurements at the climate and weather station at Forschungszentrum Jülich , where meteorological measurements and climatological observations have been carried out regularly since 1961.
• An example of the first long-term observations of the weather is Kilian Leib's handwritten weather diary from 1513 to 1531 , probably motivated by the monastery’s own agriculture. He recorded his observations daily in ephemeris (“how it thundered every day, or when it rained”); to the right of the indication of the position of the celestial bodies of the respective day, he noted the weather conditions, such as lightning strikes, hail, floods, cold snaps. He recorded the effects of the weather at the bottom and top of each page, in particular the development of the agriculturally important crops: sowing, flowering, harvesting, but also consequences such as rising prices.
• Long-term measurements over the period from 1992 to 2003 in East Antarctica , in which an increase in the ice sheet of 45 cm was measured, which is explained by the fact that the increased evaporation over the oceans leads to increased snowfall in the cold East Antarctica.
• Long-term measurements of radiocarbon in atmospheric carbon dioxide at the University of Heidelberg to observe the increase in greenhouse gas since the 1990s.
• Decades of geomagnetic field measurements with the Adolf Schmidt Observatory for Geomagnetism at the GeoForschungsZentrum Potsdam .
• Long-term geodetic investigations on the lunar surface in the years 1969 to 1977 by the Apollo Lunar Surface Experiments Package ( ALSEP ), a scientific device complex with which - as before - extremely precise distance measurements of the moon from the earth are made possible by measuring the time of flight of a laser pulse. In 2011 it became known that a new evaluation of the approximately 13,000 recorded moonquakes by the seismometers had led to new results with regard to the interior of the moon, in particular the detection of a liquid core.
• The astronomical research programs of Cuno Hoffmeister at the Sonneberg observatory , which were started in 1924 and of which the "Sonneberg Sky Monitoring" , based on Paul Guthnick's idea of monitoring the entire northern starry sky by means of astrophotography , continues to this day.
• The Voyager program NASA to explore the outer solar system and interstellar space, which includes the research mission of the space probes Voyager 1 and Voyager 2, launched in 1977 and after are active as they move through space. The probe Voyager 1 left the heliosphere in 2012 and reached interstellar space, Voyager 2 followed in 2018.

Long-term experiments

• High-energy physics experiments at the HERA particle accelerator at DESY from 1994 to 2007, which in turn were accompanied by various measurements for calibration and quality assurance, such as B. through experiments to measure the properties of the optical components on the ZEUS detector over a period of 17 years (during which a very weak but systematic cloudiness of the scintillators of the calorimeter was found).
• The University of Queensland Australia's 1927 pitch drop experiment that measures the flow of viscous liquids. E.g. Bitumen melts extremely slowly at room temperature, so that several years pass before a single drop forms.

This list can be expanded to include a multitude of other examples of long-term studies from the sciences.

See also

• experiment
• Random experiment
• Cohort study and longitudinal study
• Field trial
• Creep test
• Long-term archiving
• Statistical design of experiments
• Quasi-experimental design

Web links

Wiktionary: Long-term study  - explanations of meanings, word origins, synonyms, translations

Individual evidence

1. ↑ Summarizing Congress Report and 6 “Key Messages” from 2009 ( Memento of the original from January 26, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed May 1, 2013. 
2. ↑ The long way to happiness , interview by Michael Saur with the head of the study, the psychologist George E. Vaillant in the magazine of the Süddeutsche Zeitung , number 13, March 28, 2013.
3. ↑ Agricultural and Horticultural Faculty of the Humboldt University of Berlin Köhn, 2002, Experimental Guide 2002, Humboldt University of Berlin, LGF, Institute for Crop Science, Research Station, accessed on May 1, 2013.
4. ↑ Institute for Nutrition u. Food sciences (IEL) at the University of Bonn , where the cohort study has been continued since January 1, 2012, accessed on May 11, 2013.
5. ↑ Climate statistics from the climate and weather station of FZ Jülich , accessed on May 1, 2013.
6. ↑ Karl Schottenloher: The Rebdorf Prior Kilian Leib and his weather diary from 1513–1531 . In: Contributions to Bavarian History, 1913, pp. 81–114, as well as Friedrich Klemm : About the meteorological observations of Prior Kilian Leib in the Augustinian Canons Rebdorf from April 22, 1513 to December 31, 1531 . In: Meteorologische Rundschau 20/3, 1967, pp. 72-77.
7. ↑ Fasbender: Leib, Kilian , 2009, Col. 43.
8. ^ Norbert W. Roland: Antarctica - Research in the Eternal Ice . Spectrum, Heidelberg (2009). ISBN 978-3-8274-1875-3 .
9. ↑ Long-term measurements of radiocarbon in atmospheric carbon dioxide at the Institute for Environmental Physics at Heidelberg University , accessed on May 1, 2013.
10. ↑ M. Korte, H.-J. Linthe, M. Mandea: 75 years of geomagnetic measurements in Niemegk: the Adolf Schmidt Observatory for Geomagnetism of the GeoForschungsZentrum Potsdam , 2005.
11. ↑ "Apollo" data: Moonquakes reveal the interior of the earth's satellite . In: SPIEGEL ONLINE . January 7, 2011. Retrieved May 18, 2011.
12. ^ Renee C. Weber, Pei-Ying Lin, Edward J. Garnero, Quentin Williams, Philippe Lognonne: Seismic Detection of the Lunar Core . In: Science . January 6, 2011. doi : 10.1126 / science.1199375 . Retrieved May 18, 2011.
13. ↑ Elena Sellentin: Voyager 1 on the last leg of her journey. In: Spektrum.de. December 5, 2012, accessed April 4, 2018 . 
14. ↑ Sean Potter: NASA's Voyager 2 Probe Enters Interstellar Space. In: NASA .gov. December 10, 2018, accessed December 1, 2019 .  
15. ↑ I. Bohnet , R.-P. Feller, N. Krumnack, E. Möller, H. Prause, H. Salehi, K. Wick: Long-term studies of the optical components in the ZEUS calorimeter using a moving ⁶⁰ Co source , Nucl. Instr. and Meth., A599 (2009) 53-59, see article in the DESY publication database , accessed on May 26, 2013.
16. ↑ R. Edgeworth, BJ Dalton, T. Parnell Edgeworth: The Pitch Drop Experiment . Retrieved October 15, 2007.
17. ^ Rob Waugh: Is this the most boring experiment ever? Scientists watch drops of pitch form - and there have been eight in 75 years . In: Daily Mail . Retrieved May 13, 2012.