Snowball

Background and Objectives Snowball sampling is applied when samples with the target characteristics are not easily accessible. This research describes snowball sampling as a purposeful method of data collection in qualitative research. Methods This paper is a descriptive review of previous research papers. Data were gathered using English keywords, including “review,” “declaration,” “snowball,” and “chain referral,” as well as Persian keywords that are equivalents of the following: “purposeful sampling,” “snowball,” “qualitative research,” and “descriptive review.” The databases included Google Scholar, Scopus, Irandoc, ProQuest, Science Direct, SID, MagIran, Medline, and Cochrane. The search was limited to Persian and English articles written between 2005 and 2013. Results The preliminary search yielded 433 articles from PubMed, 88 articles from Scopus, 1 article from SID, and 18 articles from MagIran. Among 125 articles, methodological and non-research articles were omitted. Finally, 11 relevant articles, which met the criteria, were selected for review. Conclusions Different methods of snowball sampling can be applied to facilitate scientific research, provide community-based data, and hold health educational programs. Snowball sampling can be effectively used to analyze vulnerable groups or individuals under special care. In fact, it allows researchers to access susceptible populations. Thus, it is suggested to consider snowball sampling strategies while working with the attendees of educational programs or samples of research studies.

Background and Objectives Snowball sampling is applied when samples with the target characteristics are not easily accessible. This research describes snowball sampling as a purposeful method of data collection in qualitative research. Methods This paper is a descriptive review of previous research papers. Data were gathered using English keywords, including “review,” “declaration,” “snowball,” and “chain referral,” as well as Persian keywords that are equivalents of the following: “purposeful sampling,” “snowball,” “qualitative research,” and “descriptive review.” The databases included Google Scholar, Scopus, Irandoc, ProQuest, Science Direct, SID, MagIran, Medline, and Cochrane. The search was limited to Persian and English articles written between 2005 and 2013. Results The preliminary search yielded 433 articles from PubMed, 88 articles from Scopus, 1 article from SID, and 18 articles from MagIran. Among 125 articles, methodological and non-research articles were omitted. Final...

Background and Objectives Snowball sampling is applied when samples with the target characteristics are not easily accessible. This research describes snowball sampling as a purposeful method of data collection in qualitative research. Methods This paper is a descriptive review of previous research papers. Data were gathered using English keywords, including “review,” “declaration,” “snowball,” and “chain referral,” as well as Persian keywords that are equivalents of the following: “purposeful sampling,” “snowball,” “qualitative research,” and “descriptive review.” The databases included Google Scholar, Scopus, Irandoc, ProQuest, Science Direct, SID, MagIran, Medline, and Cochrane. The search was limited to Persian and English articles written between 2005 and 2013. Results The preliminary search yielded 433 articles from PubMed, 88 articles from Scopus, 1 article from SID, and 18 articles from MagIran. Among 125 articles, methodological and non-research articles were omitted. Final...

El present treball té per finalitat conèixer les pràctiques de risc per la salut associades al consum de substàncies psicoactives de les persones internades al Centre Penitenciari Brians 1. S’han combinat mètodes d’investigació quantitatius amb d’altres qualitatius per poder accedir a les poblacions ocultes així com a les experiències subjectives dels participants.

Els principals resultats obtinguts manifesten l’existència de nivells de problemes de salut sensiblement superiors als trobats en la població general i en la majoria d’estudis penitenciaris. Existeixen dues tipologies d’addictes –els funcionals (tipus A) i els crònics (tipus B)-, relacionades tant amb problemes de salut (física i mental) com socials o de conducta delictiva. Aquestes tipologies mostren actituds davant el risc que poden ser ‘prudents’, ‘aventureres’ o ‘temeràries’.

Altres resultats rellevants inclouen el paper de les variables de tractament de drogues com a factors de risc i el de les relacions socials com a variables protectores, així com les diferències de gènere en la motivació pel tractament.

Proposem un seguit d’actuacions per abordar aquests problemes dins del model d’intervenció motivacional de reducció de danys, centrat en les necessitats de la persona i d’acompanyament en els processos de recuperació, en el marc de les diferents accions de promoció de la salut que ja es fan, i de les que destaquem especialment  l’educació entre iguals – Programa d’Agents de Salut (PAS) – i l’Intercanvi de Xeringues (PIX).

The present study was an attempt to look into the effect of collaborative learning on the learners' improvement in vocabulary learning. Moreover, the learners' attitudes about vocabulary learning were taken into account as well. The study was conducted with the participation of 30 intermediate Iranian EFL (English as a foreign language) learners, who were studying in a private language institute. To collect the data, OPT (Oxford Placement Test) was applied to check the learners' proficiency level and meet the homogeneity requirements. Then, the learners took the vocabulary pre-and post-test to check the effectiveness of treatment sessions on the learners' vocabulary learning. Semi-structured interview was also done to investigate the learners' awareness regarding learning vocabularies before and after the treatment sessions. Findings showed that the applied collaborative techniques, i.e. word-webbing and snowball techniques paved the way for the experimental group to outperform the control group since improvement in vocabulary learning was found to be significant. Moreover, Qualitative results revealed the occurrence of positive changes in the learners' attitudes about vocabulary learning since almost all the learners concurred that the above-mentioned collaborative techniques assisted them in their better speaking and, by having more interaction through group work, enjoyable environment was created for learning target vocabularies. It was suggested that collaborative instruction should be implemented in teaching vocabulary as it can pave the way for both teachers and learners to benefit from a communicative language classroom.

Despite the vast extent of the Arabian Nubian Shield (ANS) and its growth during the renowned Neoproterzoic dramatic climatic changes (Snowball Earth Events), only few records of snowball events are identified among its rocks. Here we present geological and geochemical evidence that the northern part of the Arabian Nubian Shield (Um Zariq Formation (UZF), southeast Sinai, Egypt) witnessed global snowball event(s). The UZF was deposited in a convergent plate margin during Cryogenian and comprises metapelitic schists and cap-carbonates on top. The whole succession underwent amphibolite facies metamorphism around 660 Ma ago. In the upper most part of the metapelitic schists, intercalations of conglomeritic, poorly sorted components and large pebbles show many features comparable to metamorphosed diamictites and dropstones. The arsenic (As) contents of metapelites are 1-3 orders of magnitude higher than average phyllites. The high As contents and the presence, cap carbonates, diamictites and dropstones at UZF point toward deposition under glacial-postglacial conditions apparently during the Sturtian (717-660 Ma) snowball event.